3. Массивы и модели;

https://job4j.ru/profile/exercise/22/task-view/155

src/main/java/ru/j4j/pojo/Book.java

@@ -0,0 +1,19 @@
+package ru.j4j.pojo;
+
+public class Book {
+    private final String nameBook;
+    private final int countPages;
+
+    public Book(String nameBook, int countPages) {
+        this.nameBook = nameBook;
+        this.countPages = countPages;
+    }
+
+    public String getNameBook() {
+        return nameBook;
+    }
+
+    public int getCountPages() {
+        return countPages;
+    }
+}

src/main/java/ru/j4j/pojo/Library.java

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+package ru.j4j.pojo;
+
+public class Library {
+    public static void main(String[] args) {
+        Book one = new Book("Clean code", 800);
+        Book two = new Book("Java", 1600);
+        Book three = new Book("PMBOK", 1200);
+        Book four = new Book("SCRUM", 15200);
+
+        Book[] books = new Book[4];
+        books[0] = one;
+        books[1] = two;
+        books[2] = three;
+        books[3] = four;
+
+        for (Book book : books) {
+            System.out.printf("Book: %s, pages: %s;" + System.lineSeparator(), book.getNameBook(), book.getCountPages());
+        }
+        System.out.println("Replace book with index 0 and 3");
+        Book temp = books[0];
+        books[0] = books[3];
+        books[3] = temp;
+
+        for (Book book : books) {
+            System.out.printf("Book: %s, pages: %s" + System.lineSeparator(), book.getNameBook(), book.getCountPages());
+        }
+        System.out.println("Find book \"Clean code\"");
+        for (Book book : books) {
+            if (book.getNameBook().equals("Clean code")) {
+                System.out.printf("Book: %s, pages: %s" + System.lineSeparator(), book.getNameBook(), book.getCountPages());
+            }
+        }
+    }
+}

src/main/java/ru/j4j/pojo/Product.java

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+package ru.j4j.pojo;
+
+public class Product {
+    private final String name;
+    private final int count;
+
+    public Product(String name, int count) {
+        this.name = name;
+        this.count = count;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getCount() {
+        return count;
+    }
+}

src/main/java/ru/j4j/pojo/Store.java

@@ -0,0 +1,30 @@
+package ru.j4j.pojo;
+
+public class Store {
+    public static void main(String[] args) {
+        Product milk = new Product("Milk", 10);
+        Product bread = new Product("Bread", 4);
+        Product egg = new Product("Egg", 19);
+
+        Product[] prods = new Product[3];
+        prods[0] = milk;
+        prods[1] = bread;
+        prods[2] = egg;
+
+        for (Product pr : prods) {
+            System.out.println(pr.getName() + " - " + pr.getCount());
+        }
+        System.out.println("Replace milk to oil.");
+        Product oil = new Product("Oil", 11);
+        prods[0] = oil;
+        for (Product pr : prods) {
+            System.out.println(pr.getName() + " - " + pr.getCount());
+        }
+        System.out.println("Shown only product.count > 10");
+        for (Product pr : prods) {
+            if (pr.getCount() > 10) {
+                System.out.println(pr.getName() + " - " + pr.getCount());
+            }
+        }
+    }
+}