diff --git a/build.gradle b/build.gradle
index a388517ae1..9c00a7e1e5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,7 @@
 plugins {
     id 'java'
     id 'application'
+    id 'checkstyle'
     id 'com.github.johnrengelman.shadow' version '7.1.2'
 }
 
@@ -28,7 +29,7 @@ test {
 }
 
 application {
-    mainClass.set("seedu.duke.Duke")
+    mainClass.set("duke.Duke")
 }
 
 shadowJar {
@@ -40,3 +41,7 @@ shadowJar {
 run{
     standardInput = System.in
 }
+
+checkstyle {
+    toolVersion = '10.2'
+}
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
new file mode 100644
index 0000000000..acac1a8e28
--- /dev/null
+++ b/config/checkstyle/checkstyle.xml
@@ -0,0 +1,434 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!--
+    This configuration file enforces rules for the coding standard at
+    https://se-education.org/guides/conventions/java/intermediate.html
+-->
+
+<module name="Checker">
+
+    <module name="FileTabCharacter">
+        <!-- Checks that there are no tab characters in the file. -->
+    </module>
+
+    <module name="NewlineAtEndOfFile">
+        <!-- Accept LF, CR or CRLF to accomodate devs who prefer different line endings -->
+        <property name="lineSeparator" value="lf_cr_crlf"/>
+    </module>
+
+    <module name="RegexpSingleline">
+        <!-- Checks that FIXME is not used in comments.  TODO is preferred. -->
+        <property name="format" value="((//.*)|(\*.*))FIXME" />
+        <property name="message" value='TODO is preferred to FIXME."' />
+    </module>
+
+    <module name="SuppressionFilter">
+        <property name="file" value="${config_loc}/suppressions.xml"/>
+    </module>
+
+    <module name="LineLength">
+        <!-- Checks if a line is too long. -->
+        <property name="max" value="120"/>
+    </module>
+
+    <!-- All Java AST specific tests live under TreeWalker module. -->
+    <module name="TreeWalker">
+
+        <!-- Required to allow exceptions in code style -->
+        <module name="SuppressionCommentFilter">
+            <property name="offCommentFormat" value="CHECKSTYLE.OFF\: ([\w\|]+)"/>
+            <property name="onCommentFormat" value="CHECKSTYLE.ON\: ([\w\|]+)"/>
+            <property name="checkFormat" value="$1"/>
+        </module>
+
+        <!--
+        IMPORT CHECKS
+        -->
+
+        <!-- Checks the ordering of import statements follow the rules that the default Eclipse formatter uses.
+        The order rule "STATIC###STANDARD_JAVA_PACKAGE###SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE" consists of:
+          1. STATIC: static imports
+          2. STANDARD_JAVA_PACKAGE: standard java/javax imports
+          3. SPECIAL_IMPORTS: defined as org imports
+          4. THIRD_PARTY_PACKAGE: defined as com imports
+        -->
+        <module name="CustomImportOrder">
+            <property name="customImportOrderRules"
+                      value="STATIC###STANDARD_JAVA_PACKAGE###SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE"/>
+            <property name="specialImportsRegExp" value="^org\."/>
+            <property name="thirdPartyPackageRegExp" value="^com\."/>
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+        </module>
+
+        <!-- Checks for redundant import statements.
+        An import statement is redundant if:
+          * It is a duplicate of another import. This is, when a class is imported more than once.
+          * The class non-statically imported is from the java.lang package, e.g. importing java.lang.String.
+          * The class non-statically imported is from the same package as the current package.
+        -->
+        <module name="RedundantImport"/>
+
+        <!-- Checks for unused import statements.
+        An import statement is unused if:
+          It's not referenced in the file.
+        -->
+        <module name="UnusedImports"/>
+
+        <module name="AvoidStarImport"/>
+
+        <!--
+        NAMING CHECKS
+        -->
+
+        <!-- Validate abbreviations (consecutive capital letters) length in identifier name -->
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="1"/>
+        </module>
+
+        <module name="PackageName">
+            <!-- Validates identifiers for package names against the supplied expression. -->
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]{1,})*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="TypeName">
+            <!-- Validates static, final fields against the expression "^[A-Z][a-zA-Z0-9]*$". -->
+            <metadata name="altname" value="TypeName"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="ConstantName">
+            <!-- Validates non-private, static, final fields against the expression "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$". -->
+            <metadata name="altname" value="ConstantName"/>
+            <property name="applyToPrivate" value="false"/>
+            <message key="name.invalidPattern"
+                     value="Variable ''{0}'' should be in ALL_CAPS (if it is a constant) or be private (otherwise)."/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="StaticVariableName">
+            <!-- Validates static, non-final fields against the supplied expression. -->
+            <metadata name="altname" value="StaticVariableName"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*_?$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="MemberName">
+            <!-- Validates non-static members against the supplied expression. -->
+            <metadata name="altname" value="MemberName"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="MethodName">
+            <!-- Validates identifiers for method names against the supplied expression. -->
+            <metadata name="altname" value="MethodName"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*(_[a-z][a-zA-Z0-9]+){0,2}$"/>
+        </module>
+
+        <module name="ParameterName">
+            <!-- Validates identifiers for method parameters against the expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="LocalFinalVariableName">
+            <!-- Validates identifiers for local final variables against the expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="LocalVariableName">
+            <!-- Validates identifiers for local variables against the expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+
+        <!--
+        LENGTH and CODING CHECKS
+        -->
+
+        <!-- Checks that array type declarations follow Java Style
+          Java style: public static void main(String[] args) // Allowed
+          C style:    public static void main(String args[]) // Not allowed
+        -->
+        <module name="ArrayTypeStyle"/>
+
+        <!-- Checks if a catch block is empty and does not contain any comments. -->
+        <module name="EmptyCatchBlock"/>
+
+        <module name="LeftCurly">
+            <!-- Checks for placement of the left curly brace ('{'). -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="RightCurly">
+            <!-- Checks right curlies on CATCH, ELSE, and TRY blocks are on
+            the same line. e.g., the following example is fine:
+            <pre>
+              if {
+                ...
+              } else
+            </pre>
+            -->
+            <!-- This next example is not fine:
+            <pre>
+              if {
+                ...
+              }
+              else
+            </pre>
+            -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <!-- Checks for braces around loop blocks -->
+        <module name="NeedBraces">
+            <!--
+            if (true) return 1; // Not allowed
+
+            if (true) { return 1; } // Not allowed
+
+            else if {
+              return 1; // else if should always be multi line
+            }
+
+            if (true)
+              return 1; // Not allowed
+            -->
+            <property name="allowEmptyLoopBody" value="true"/>
+        </module>
+
+        <!-- Checks that each variable declaration is in its own statement and on its own line. -->
+        <module name="MultipleVariableDeclarations"/>
+
+        <module name="OneStatementPerLine"/>
+
+        <!-- Checks that long constants are defined with an upper ell.-->
+        <module name="UpperEll" />
+
+        <module name="FallThrough">
+            <!-- Warn about falling through to the next case statement.  Similar to
+            javac -Xlint:fallthrough, but the check is suppressed if a single-line comment
+            on the last non-blank line preceding the fallen-into case contains 'fall through' (or
+            some other variants which we don't publicized to promote consistency).
+            -->
+            <property name="reliefPattern"
+                      value="fall through|Fall through|fallthru|Fallthru|falls through|Falls through|fallthrough|Fallthrough|No break|NO break|no break|continue on"/>
+        </module>
+
+        <module name="MissingSwitchDefault"/>
+
+        <!-- Checks that Class variables should never be declared public. -->
+        <module name="VisibilityModifier">
+            <property name="protectedAllowed" value="true"/>
+            <property name="allowPublicFinalFields" value="true"/>
+            <property name="ignoreAnnotationCanonicalNames" value="RegisterExtension, TempDir"/>
+        </module>
+
+        <!--
+        ORDER CHECKS
+        -->
+
+        <!-- Checks that the order of at-clauses follows the tagOrder default property value order.
+             @author, @version, @param, @return, @throws, @exception, @see, @since, @serial, @serialField, @serialData, @deprecated
+        -->
+        <module name="AtclauseOrder"/>
+
+        <!-- Checks if the Class and Interface declarations is organized in this order
+          1. Class (static) variables. Order: public, protected, package level (no access modifier), private.
+          2. Instance variables. Order: public, protected, package level (no access modifier), private.
+          3. Constructors
+          4. Methods
+        -->
+        <module name ="DeclarationOrder"/>
+
+        <!-- Checks that default is after all cases in a switch statement -->
+        <module name="DefaultComesLast"/>
+
+        <module name="ModifierOrder">
+            <!-- Warn if modifier order is inconsistent with JLS3 8.1.1, 8.3.1, and
+                 8.4.3.  The prescribed order is:
+                 public, protected, private, abstract, static, final, transient, volatile,
+                 synchronized, native, strictfp
+              -->
+        </module>
+
+        <module name="OverloadMethodsDeclarationOrder"/>
+
+        <!--
+        WHITESPACE CHECKS
+        -->
+
+        <!-- Checks that comments are indented relative to their position in the code -->
+        <module name="CommentsIndentation"/>
+
+        <module name="WhitespaceAround">
+            <!-- Checks that various tokens are surrounded by whitespace.
+                 This includes most binary operators and keywords followed
+                 by regular or curly braces.
+            -->
+            <property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR,
+        BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN,
+        EQUAL, GE, GT, LAND, LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE,
+        LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN,
+        LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS,
+        MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION,
+        RCURLY, SL, SLIST, SL_ASSIGN, SR_ASSIGN, STAR, STAR_ASSIGN"/>
+            <!-- Allow empty constructors e.g. MyClass() {} -->
+            <property name="allowEmptyConstructors" value="true" />
+            <!-- Allow empty methods e.g. void func() {} -->
+            <property name="allowEmptyMethods" value="true" />
+            <!-- Allow empty types e.g. class Foo {}, enum Foo {} -->
+            <property name="allowEmptyTypes" value="true" />
+            <!-- Allow empty loops e.g. for (int i = 1; i > 1; i++) {} -->
+            <property name="allowEmptyLoops" value="true" />
+            <!-- Allow empty lambdas e.g. () -> {} -->
+            <property name="allowEmptyLambdas" value="true" />
+        </module>
+
+        <module name="WhitespaceAfter">
+            <!-- Checks that commas, semicolons and typecasts are followed by whitespace. -->
+            <property name="tokens" value="COMMA, SEMI, TYPECAST"/>
+        </module>
+
+        <module name="NoWhitespaceAfter">
+            <!-- Checks that there is no whitespace after various unary operators. Linebreaks are allowed. -->
+            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS,
+        UNARY_PLUS"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+
+        <!-- No trailing whitespace -->
+        <module name="Regexp">
+            <property name="format" value="[ \t]+$"/>
+            <property name="illegalPattern" value="true"/>
+            <property name="message" value="Trailing whitespace"/>
+        </module>
+
+        <module name="OperatorWrap">
+            <!-- Checks that the non-assignment type operator is at the next line in a line wrap.
+                 This includes "?", ":", "==", "!=", "/", "+", "-", "*", "%", ">>", ">>>",
+                 ">=", ">", "<<", "<=", "<", "^", "|", "||", "&", "&&", "instanceof",
+                 "&" when used in a generic upper or lower bounds constraints,
+                   e.g. <T extends Foo & Bar>
+                 "::" when used as a reference to a method or constructor without arguments.
+                   e.g. String::compareToIgnoreCase
+            -->
+            <property name="tokens" value="QUESTION, COLON, EQUAL, NOT_EQUAL, DIV, PLUS, MINUS, STAR, MOD, SR, BSR,
+        GE, GT, SL, LE, LT, BXOR, BOR, LOR, BAND, LAND, LITERAL_INSTANCEOF, TYPE_EXTENSION_AND, METHOD_REF"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="OperatorWrap">
+            <!-- Checks that the assignment type operator is at the previous end of line in a line wrap.
+                 This includes "=", "/=", "+=", "-=", "*=", "%=", ">>=", ">>>=", "<<=", "^=", "&=".
+            -->
+            <property name="tokens" value="ASSIGN, DIV_ASSIGN, PLUS_ASSIGN, MINUS_ASSIGN, STAR_ASSIGN, MOD_ASSIGN,
+        SR_ASSIGN, BSR_ASSIGN, SL_ASSIGN, BXOR_ASSIGN, BOR_ASSIGN, BAND_ASSIGN"/>
+            <property name="option" value="eol"/>
+        </module>
+
+        <module name="SeparatorWrap">
+            <!-- Checks that the ".", "@" is at the next line in a line wrap. -->
+            <property name="tokens" value="DOT, AT"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- Checks that the ",", "]", "[", "...", ";", "(" is at the previous end of line in a line wrap. -->
+            <property name="tokens" value="COMMA, RBRACK, ARRAY_DECLARATOR, ELLIPSIS, SEMI, LPAREN"/>
+            <property name="option" value="eol"/>
+        </module>
+
+        <module name="Indentation">
+            <property name="caseIndent" value="0" />
+            <property name="throwsIndent" value="8" />
+        </module>
+
+        <module name="NoWhitespaceBefore">
+            <!-- Checks that there is no whitespace before various unary operators. Linebreaks are allowed. -->
+            <property name="tokens" value="SEMI, DOT, POST_DEC, POST_INC"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+
+        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
+
+        <!-- Checks that there is no whitespace between method/constructor name and open parenthesis. -->
+        <module name="MethodParamPad"/>
+
+        <module name="ParenPad">
+            <!-- Checks that there is no whitespace before close parenthesis or after open parenthesis. -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <!-- Checks that non-whitespace characters are separated by no more than one whitespace character.
+             a = 1; // Allowed
+             a  = 1; // Not allowed (more than one space before =)
+        -->
+        <module name="SingleSpaceSeparator">
+            <!-- Validate whitespace surrounding comments as well.
+
+                 a = 1; // Allowed (single space before start of comment)
+                 a = 1; /* Allowed (single space before start of comment) */
+                 /* Allowed (single space after end of comment) */ a = 1;
+                 a = 1;  // Not allowed (more than one space before start of comment)
+                 a = 1;  /* Not allowed (more than one space before start of comment) */
+                 /* Not allowed (more than one space after end of comment) */  a = 1;
+
+                 This doesn't validate whitespace within comments so a comment /* like  this */ is allowed.
+            -->
+            <property name="validateComments" value="true"/>
+        </module>
+
+        <!--
+        JAVADOC CHECKS
+        -->
+
+        <!-- Checks that all block-tags are ordered correctly. -->
+        <module name="AtclauseOrder"/>
+
+        <!-- Checks that Javadoc block tags appear only at the beginning of the line. -->
+        <module name="JavadocBlockTagLocation"/>
+
+        <!-- Checks that all Javadoc comments start from the second line. -->
+        <module name="JavadocContentLocationCheck" />
+
+        <!-- Checks that each line in Javadoc has leading asterisks. -->
+        <module name="JavadocMissingLeadingAsterisk"/>
+
+        <!-- Checks that each non-empty line in Javadoc has whitespace after leading asterisk. -->
+        <module name="JavadocMissingWhitespaceAfterAsterisk"/>
+
+        <!-- Checks that for block tags, indentation of continuation lines is at least 4 spaces. -->
+        <module name="JavadocTagContinuationIndentation"/>
+
+        <!-- Checks the Javadoc's format for every class, enumeration and interface. -->
+        <module name="JavadocType">
+            <property name="allowMissingParamTags" value="true"/>
+        </module>
+
+        <!-- Checks the Javadoc's format for every public method (excluding getters, setters and constructors). -->
+        <module name="JavadocMethod">
+            <property name="allowedAnnotations" value="Override, Test, BeforeAll, BeforeEach, AfterAll, AfterEach, Subscribe"/>
+            <property name="accessModifiers" value="public"/>
+            <property name="validateThrows" value="false"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="tokens" value="METHOD_DEF, ANNOTATION_FIELD_DEF"/>
+        </module>
+
+        <module name="InvalidJavadocPosition"/>
+
+        <!-- Checks that every public method (excluding getters, setters and constructors) has a header comment. -->
+        <module name="MissingJavadocMethodCheck">
+            <property name="minLineCount" value="1"/>
+            <property name="allowMissingPropertyJavadoc" value="true"/>
+            <property name="ignoreMethodNamesRegex" value="(set.*|get.*|main)"/>
+        </module>
+
+        <!-- Checks that every public class, enumeration and interface has a header comment. -->
+        <module name="MissingJavadocType"/>
+
+    </module>
+</module>
\ No newline at end of file
diff --git a/config/checkstyle/suppressions.xml b/config/checkstyle/suppressions.xml
new file mode 100644
index 0000000000..135ea49ee0
--- /dev/null
+++ b/config/checkstyle/suppressions.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+        "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<suppressions>
+    <suppress checks="JavadocType" files=".*Test\.java"/>
+    <suppress checks="MissingJavadocMethodCheck" files=".*Test\.java"/>
+</suppressions>
\ No newline at end of file
diff --git a/data/tasks.txt b/data/tasks.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/main/java/duke/Duke.java b/src/main/java/duke/Duke.java
index 1aa1e7977c..60dc37c7bc 100644
--- a/src/main/java/duke/Duke.java
+++ b/src/main/java/duke/Duke.java
@@ -35,7 +35,7 @@ public void run() {
             }
         }
     }
-    public static void main(String[] args){
+    public static void main(String[] args) {
         new Duke("data/tasks.txt").run();
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/duke/Parser.java b/src/main/java/duke/Parser.java
index 058ca2879a..0fcaf968fc 100644
--- a/src/main/java/duke/Parser.java
+++ b/src/main/java/duke/Parser.java
@@ -1,6 +1,12 @@
 package duke;
 
-import duke.command.*;
+import duke.command.AddCommand;
+import duke.command.Command;
+import duke.command.DeleteCommand;
+import duke.command.ExitCommand;
+import duke.command.ListCommand;
+import duke.command.MarkCommand;
+import duke.command.UnmarkCommand;
 import duke.exception.InvalidArgumentException;
 import duke.task.Deadline;
 import duke.task.Event;
@@ -14,51 +20,51 @@ public enum CommandType {
     public static Command parse(String userInput) throws InvalidArgumentException {
         CommandType commandType = parseCommand(userInput);
         switch (commandType) {
-            case LIST:
-                return new ListCommand();
+        case LIST:
+            return new ListCommand();
 
-            case DELETE:
-                // Extract the index to delete
-                int deleteIndex = Integer.parseInt(userInput.split(" ")[1]);
-                return new DeleteCommand(deleteIndex);
+        case DELETE:
+            // Extract the index to delete
+            int deleteIndex = Integer.parseInt(userInput.split(" ")[1]);
+            return new DeleteCommand(deleteIndex);
 
-            case MARK:
-                // Extract the index to mark
-                int markIndex = Integer.parseInt(userInput.split(" ")[1]);
-                return new MarkCommand(markIndex);
+        case MARK:
+            // Extract the index to mark
+            int markIndex = Integer.parseInt(userInput.split(" ")[1]);
+            return new MarkCommand(markIndex);
 
-            case UNMARK:
-                // Extract the index to unmark
-                int unmarkIndex = Integer.parseInt(userInput.split(" ")[1]);
-                return new UnmarkCommand(unmarkIndex);
+        case UNMARK:
+            // Extract the index to unmark
+            int unmarkIndex = Integer.parseInt(userInput.split(" ")[1]);
+            return new UnmarkCommand(unmarkIndex);
 
-            case ADD:
-                if (userInput.startsWith("todo")) {
-                    String taskName = userInput.substring(5).trim();
-                    return new AddCommand(new Todo(taskName));
-                } else {
-                    String trim = userInput.substring(userInput.indexOf(' ') + 1).trim();
-                    if (userInput.startsWith("deadline")) {
-                        int deadlineIndex = trim.indexOf("/by");
-                        String taskDeadline = trim.substring(deadlineIndex + 4).trim();
-                        String taskName = trim.substring(0, deadlineIndex).trim();
-                        return new AddCommand(new Deadline(taskName, taskDeadline));
-                    } else if (userInput.startsWith("event")) {
-                        int fromIndex = trim.indexOf("/from");
-                        int toIndex = trim.indexOf("/to");
-                        String taskFrom = trim.substring(fromIndex + 6, toIndex - 1).trim();
-                        String taskTo = trim.substring(toIndex + 4).trim();
-                        String taskName = trim.substring(0, fromIndex).trim();
-                        return new AddCommand(new Event(taskName, taskFrom, taskTo));
-                    }
+        case ADD:
+            if (userInput.startsWith("todo")) {
+                String taskName = userInput.substring(5).trim();
+                return new AddCommand(new Todo(taskName));
+            } else {
+                String trim = userInput.substring(userInput.indexOf(' ') + 1).trim();
+                if (userInput.startsWith("deadline")) {
+                    int deadlineIndex = trim.indexOf("/by");
+                    String taskDeadline = trim.substring(deadlineIndex + 4).trim();
+                    String taskName = trim.substring(0, deadlineIndex).trim();
+                    return new AddCommand(new Deadline(taskName, taskDeadline));
+                } else if (userInput.startsWith("event")) {
+                    int fromIndex = trim.indexOf("/from");
+                    int toIndex = trim.indexOf("/to");
+                    String taskFrom = trim.substring(fromIndex + 6, toIndex - 1).trim();
+                    String taskTo = trim.substring(toIndex + 4).trim();
+                    String taskName = trim.substring(0, fromIndex).trim();
+                    return new AddCommand(new Event(taskName, taskFrom, taskTo));
                 }
-                break;
+            }
+            break;
 
-            case BYE:
-                return new ExitCommand();
+        case BYE:
+            return new ExitCommand();
 
-            default:
-                throw new InvalidArgumentException();
+        default:
+            throw new InvalidArgumentException();
         }
 
         return null;
diff --git a/src/main/java/duke/Storage.java b/src/main/java/duke/Storage.java
index 5a8e8dfb81..5707c71587 100644
--- a/src/main/java/duke/Storage.java
+++ b/src/main/java/duke/Storage.java
@@ -1,11 +1,5 @@
 package duke;
 
-import duke.exception.InvalidArgumentException;
-import duke.task.Deadline;
-import duke.task.Event;
-import duke.task.Task;
-import duke.task.Todo;
-
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileWriter;
@@ -14,6 +8,12 @@
 import java.util.List;
 import java.util.Scanner;
 
+import duke.exception.InvalidArgumentException;
+import duke.task.Deadline;
+import duke.task.Event;
+import duke.task.Task;
+import duke.task.Todo;
+
 public class Storage {
     private final String filePath;
 
@@ -57,7 +57,7 @@ public void save(TaskList list) {
             System.out.println("An error occurred while saving tasks to disk.");
         }
     }
-    private static Task parseFromFile(String line) throws InvalidArgumentException{
+    private static Task parseFromFile(String line) throws InvalidArgumentException {
         String[] parts = line.split(" \\| ");
         String type = parts[0];
         boolean isDone = parts[1].equals("1");
@@ -66,22 +66,22 @@ private static Task parseFromFile(String line) throws InvalidArgumentException{
         Task task;
 
         switch (type) {
-            case "T":
-                task = new Todo(description);
-                break;
-            case "D":
-                String deadline = parts[3];
-                task = new Deadline(description, deadline);
-                break;
-            case "E":
-                String eventTime = parts[3];
-                int toIndex = eventTime.indexOf("to");
-                String from = eventTime.substring(0, toIndex).trim();
-                String to = eventTime.substring(toIndex + 2).trim();
-                task = new Event(description, from, to);
-                break;
-            default:
-                throw new InvalidArgumentException();
+        case "T":
+            task = new Todo(description);
+            break;
+        case "D":
+            String deadline = parts[3];
+            task = new Deadline(description, deadline);
+            break;
+        case "E":
+            String eventTime = parts[3];
+            int toIndex = eventTime.indexOf("to");
+            String from = eventTime.substring(0, toIndex).trim();
+            String to = eventTime.substring(toIndex + 2).trim();
+            task = new Event(description, from, to);
+            break;
+        default:
+            throw new InvalidArgumentException();
         }
 
         if (isDone) {
diff --git a/src/main/java/duke/TaskList.java b/src/main/java/duke/TaskList.java
index 3ab7e4ad0b..afbc423b1d 100644
--- a/src/main/java/duke/TaskList.java
+++ b/src/main/java/duke/TaskList.java
@@ -1,12 +1,12 @@
 package duke;
 
-import duke.task.Task;
-
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
-public class TaskList implements Iterable<Task>{
+import duke.task.Task;
+
+public class TaskList implements Iterable<Task> {
     private List<Task> tasks;
 
     public TaskList() {
diff --git a/src/main/java/duke/Ui.java b/src/main/java/duke/Ui.java
index d50234c64c..c1419bc871 100644
--- a/src/main/java/duke/Ui.java
+++ b/src/main/java/duke/Ui.java
@@ -1,23 +1,23 @@
 package duke;
 
-import duke.task.Task;
-
 import java.util.Scanner;
 
+import duke.task.Task;
+
 public class Ui {
-    String logo = "    ___    _   ___   ________  __      ____      __________  ____  _   __\n"
-            + "   /   |  / | / / | / / __ \\ \\/ /     / __ \\    /_  __/ __ \\/ __ \\/ | / /\n"
-            + "  / /| | /  |/ /  |/ / / / /\\  /_____/ / / /_____/ / / /_/ / / / /  |/ / \n"
-            + " / ___ |/ /|  / /|  / /_/ / / /_____/ /_/ /_____/ / / _, _/ /_/ / /|  /  \n"
-            + "/_/  |_/_/ |_/_/ |_/\\____/ /_/      \\____/     /_/ /_/ |_|\\____/_/ |_/   \n";
-    String horizontalLine = "__________________________________________________________________________";
-    String byeMessage = "Bye. Hope to see you again soon!";
+    private String horizontalLine = "__________________________________________________________________________";
 
     public void showWelcome() {
+        String logo = "    ___    _   ___   ________  __      ____      __________  ____  _   __\n"
+                + "   /   |  / | / / | / / __ \\ \\/ /     / __ \\    /_  __/ __ \\/ __ \\/ | / /\n"
+                + "  / /| | /  |/ /  |/ / / / /\\  /_____/ / / /_____/ / / /_/ / / / /  |/ / \n"
+                + " / ___ |/ /|  / /|  / /_/ / / /_____/ /_/ /_____/ / / _, _/ /_/ / /|  /  \n"
+                + "/_/  |_/_/ |_/_/ |_/\\____/ /_/      \\____/     /_/ /_/ |_|\\____/_/ |_/   \n";
         System.out.println(horizontalLine + logo + "Hello! I'm ANNOY-O-TRON!\nWhat can I do for you?\n"
                 + horizontalLine);
     }
     public void showBye() {
+        String byeMessage = "Bye. Hope to see you again soon!";
         System.out.println(byeMessage);
     }
     public void showLine() {
diff --git a/src/main/java/duke/command/AddCommand.java b/src/main/java/duke/command/AddCommand.java
index 4187ff1a91..7ed6277337 100644
--- a/src/main/java/duke/command/AddCommand.java
+++ b/src/main/java/duke/command/AddCommand.java
@@ -5,7 +5,7 @@
 import duke.Ui;
 import duke.task.Task;
 
-public class AddCommand extends Command{
+public class AddCommand extends Command {
     private Task task;
 
     public AddCommand(Task task) {
diff --git a/src/main/java/duke/command/DeleteCommand.java b/src/main/java/duke/command/DeleteCommand.java
index cb875cc323..fcb5eb7350 100644
--- a/src/main/java/duke/command/DeleteCommand.java
+++ b/src/main/java/duke/command/DeleteCommand.java
@@ -19,4 +19,4 @@ public void execute(TaskList tasks, Ui ui, Storage storage) {
         ui.showNumberOfTasks(tasks);
         storage.save(tasks);
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/duke/command/ExitCommand.java b/src/main/java/duke/command/ExitCommand.java
index 4de7b54d76..44b817cb4e 100644
--- a/src/main/java/duke/command/ExitCommand.java
+++ b/src/main/java/duke/command/ExitCommand.java
@@ -3,7 +3,6 @@
 import duke.Storage;
 import duke.TaskList;
 import duke.Ui;
-import duke.command.Command;
 
 public class ExitCommand extends Command {
     public ExitCommand() {
diff --git a/src/main/java/duke/command/ListCommand.java b/src/main/java/duke/command/ListCommand.java
index 4e667a36c4..07503ad336 100644
--- a/src/main/java/duke/command/ListCommand.java
+++ b/src/main/java/duke/command/ListCommand.java
@@ -3,7 +3,6 @@
 import duke.Storage;
 import duke.TaskList;
 import duke.Ui;
-import duke.command.Command;
 
 public class ListCommand extends Command {
     @Override
diff --git a/src/main/java/duke/command/MarkCommand.java b/src/main/java/duke/command/MarkCommand.java
index c1fa9f516f..271c320023 100644
--- a/src/main/java/duke/command/MarkCommand.java
+++ b/src/main/java/duke/command/MarkCommand.java
@@ -3,7 +3,6 @@
 import duke.Storage;
 import duke.TaskList;
 import duke.Ui;
-import duke.command.Command;
 import duke.task.Task;
 
 public class MarkCommand extends Command {
diff --git a/src/main/java/duke/command/UnmarkCommand.java b/src/main/java/duke/command/UnmarkCommand.java
index 829ee265af..92b82275ba 100644
--- a/src/main/java/duke/command/UnmarkCommand.java
+++ b/src/main/java/duke/command/UnmarkCommand.java
@@ -3,7 +3,6 @@
 import duke.Storage;
 import duke.TaskList;
 import duke.Ui;
-import duke.command.Command;
 import duke.task.Task;
 
 public class UnmarkCommand extends Command {
diff --git a/src/main/java/duke/exception/DukeException.java b/src/main/java/duke/exception/DukeException.java
index cc86b9129d..2a9671b53b 100644
--- a/src/main/java/duke/exception/DukeException.java
+++ b/src/main/java/duke/exception/DukeException.java
@@ -1,6 +1,6 @@
 package duke.exception;
 
-public class DukeException extends Exception{
+public class DukeException extends Exception {
     public DukeException(String errorMessage) {
         super("☹ OOPS!!! " + errorMessage);
     }
diff --git a/src/main/java/duke/exception/EmptyDescriptionException.java b/src/main/java/duke/exception/EmptyDescriptionException.java
index c97079d761..d7726297c3 100644
--- a/src/main/java/duke/exception/EmptyDescriptionException.java
+++ b/src/main/java/duke/exception/EmptyDescriptionException.java
@@ -1,7 +1,5 @@
 package duke.exception;
 
-import duke.exception.DukeException;
-
 public class EmptyDescriptionException extends DukeException {
     public EmptyDescriptionException() {
         super("The description of a todo cannot be empty.");
diff --git a/src/main/java/duke/exception/InvalidArgumentException.java b/src/main/java/duke/exception/InvalidArgumentException.java
index 8ee02222d8..423ba3dde4 100644
--- a/src/main/java/duke/exception/InvalidArgumentException.java
+++ b/src/main/java/duke/exception/InvalidArgumentException.java
@@ -1,7 +1,5 @@
 package duke.exception;
 
-import duke.exception.DukeException;
-
 public class InvalidArgumentException extends DukeException {
     public InvalidArgumentException() {
         super("I'm sorry, but I don't know what that means :-(");
diff --git a/src/main/java/duke/task/Deadline.java b/src/main/java/duke/task/Deadline.java
index 960e463e34..07d5680370 100644
--- a/src/main/java/duke/task/Deadline.java
+++ b/src/main/java/duke/task/Deadline.java
@@ -1,7 +1,5 @@
 package duke.task;
 
-import duke.task.Task;
-
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 
diff --git a/src/main/java/duke/task/Event.java b/src/main/java/duke/task/Event.java
index 7fb62607f2..ec1a767665 100644
--- a/src/main/java/duke/task/Event.java
+++ b/src/main/java/duke/task/Event.java
@@ -18,12 +18,14 @@ public Event(String description, String from, String to) {
     @Override
     public String toString() {
         DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MMM dd yyyy, HH:mm");
-        return "[E]" + super.toString() + " (from: " + this.from.format(formatter) + " to: " + this.to.format(formatter) + ")";
+        return "[E]" + super.toString() + " (from: " + this.from.format(formatter) + " to: "
+                + this.to.format(formatter) + ")";
     }
 
     @Override
     public String toFileString() {
         DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HHmm");
-        return "E | " + (isDone ? "1" : "0") + " | " + this.description + " | " + this.from.format(formatter) + " to " + this.to.format(formatter);
+        return "E | " + (isDone ? "1" : "0") + " | " + this.description + " | " + this.from.format(formatter)
+                + " to " + this.to.format(formatter);
     }
 }
diff --git a/src/main/java/duke/task/Task.java b/src/main/java/duke/task/Task.java
index 1b66222a10..d97970ce7f 100644
--- a/src/main/java/duke/task/Task.java
+++ b/src/main/java/duke/task/Task.java
@@ -30,4 +30,4 @@ public String toFileString() {
         return " | " + (isDone ? "1" : "0") + " | " + this.description;
     }
 
-}
\ No newline at end of file
+}
diff --git a/src/main/java/duke/task/Todo.java b/src/main/java/duke/task/Todo.java
index f0d1280245..1417acadc8 100644
--- a/src/main/java/duke/task/Todo.java
+++ b/src/main/java/duke/task/Todo.java
@@ -1,7 +1,5 @@
 package duke.task;
 
-import duke.task.Task;
-
 public class Todo extends Task {
     public Todo(String description) {
         super(description);