sort lists with reverse and joining them

src/test/java/com/finance/programming/ListExercises.java

@@ -3,11 +3,12 @@
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
+import java.util.Comparator;
 import java.util.List;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.*;
 
 @DisplayName("Working with lists")
 public class ListExercises {
@@ -29,8 +30,40 @@ void testListOfEvenNumbers(){
 
         assertEquals(evenNumbers, actualEvenNumbers);
 
+    }
+
+    @Test
+    @DisplayName("test Join a list of strings")
+    void testJoinAListOfStrings(){
+        // Convert a list of strings into a single comma-separated string using Collectors.joining.
+        List<String> listOfString = List.of("Spring", "Microservices", "Boot", "Test");
+        String  expectedString = "Spring,Microservices,Boot,Test";
 
+//        String actualString = String.join(",", listOfString);
+        String actualString = listOfString.stream()
+                .collect(Collectors.joining(","));
+
+        assertEquals(expectedString, actualString);
     }
 
 
+    @Test
+    @DisplayName(": Sort a list of strings in reverse alphabetical order using streams.")
+    void testSortAListOfStrings(){
+        List<String> listOfString = List.of("spa", "zar", "tool", "alp", "toy");
+        List<String> expectedList = List.of("zar", "toy", "tool", "spa", "alp");
+        List<String> actualList = listOfString.stream()
+                .sorted(Comparator.reverseOrder())
+                .toList();
+
+        assertIterableEquals(expectedList, actualList, "The list doesn't match");
+
+        assertNotEquals(
+                expectedList,
+                listOfString.stream().sorted(Comparator.naturalOrder()).toList(),
+                "The list must not be equals"
+
+        );
+    }
+
 }

tests.md

@@ -31,10 +31,10 @@ Description: Use reduce to sum all the elements of a list of integers.
 ✔️ **Exercise 9: Using flatMap**
 Description: Take a list of lists of integers and use flatMap to convert it into a flat list of integers.
 
-❌ **Exercise 10: Sorting a list**
+✔️ **Exercise 10: Sorting a list**
 Description: Sort a list of strings in reverse alphabetical order using streams.
 
-❌ **Exercise 11: Using collect**
+✔️ **Exercise 11: Using collect**
 Description: Convert a list of strings into a single comma-separated string using Collectors.joining.
 
 ❌ **Exercise 12: Creating an infinite Stream**