oop : variable, data type, assign

JavaOOP/src/Java01.java

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+public class Java01 {
+
+    public static void main(String[] args) {
+        System.out.println("hello world");
+    }
+}

JavaOOP/src/Java02.java

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+import object.Book;
+
+public class Java02 {
+    public static void main(String[] args) {
+        // 프로그래밍 3대 요소 - 변수, 자료형, 할당
+        // {자료형} {변수} = {할당}
+        int a = 1, b = 1, c = a + b;
+        System.out.println(c);
+
+        float f = 34.5f;
+        System.out.println(f);
+
+        char d = 'A';
+        System.out.println(d);
+
+        boolean g = true;
+        System.out.println(g);
+
+        Book book;
+    }
+}

JavaOOP/src/Java03.java

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+import object.Book;
+import object.Person;
+
+public class Java03 {
+
+    public static void main(String[] args) {
+        // 관계를 이해하라. PDT vs UDDT
+
+        // 정수 1개를 저장하기 위한 변수를 선언하시오.
+        int a = 10;
+
+        // 책 1권을 저장하기 위한 선언하시오.
+        Book b = new Book();
+        b.title = "자바";
+        b.price = 15000;
+        b.company = "한빛미디어";
+        b.page = 700;
+
+        System.out.println(b.title);
+        System.out.println(b.price);
+        System.out.println(b.company);
+        System.out.println(b.page);
+
+        Person p = new Person();
+        p.name = "홍길동";
+        p.age = 20;
+        p.weight = 78.9f;
+        p.height = 184.8f;
+
+        System.out.println(p.name);
+        System.out.println(p.age);
+        System.out.println(p.weight);
+        System.out.println(p.height);
+    }
+}

JavaOOP/src/object/Book.java

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+package object;
+
+public class Book {
+    public String title;
+    public int price;
+    public String company;
+    public int page;
+}

JavaOOP/src/object/Person.java

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+package object;
+
+public class Person {
+    public String name;
+    public int age;
+    public float weight;
+    public float height;
+}