[자바] wrapper 클래스

public class Wrapper1 {
 
    public static void main(String[] args) {
 
        Integer i1 = new Integer(100); // 인스턴스생성
        Integer i2 = new Integer(100); // 인스턴스 생성
        
        System.out.println("참조변수의 비교 : " + (i1==i2)); // 참조값비교
        System.out.println("저장값 비교 : " + i1.equals(i2)); // 저장값 비교
        
        System.out.println("il.toString() : "+ i1.toString());
        System.out.println("i2.toString() : "+ i2.toString());
        
        System.out.println("Integer.MAX_VALUE : " +Integer.MAX_VALUE);
        System.out.println("Integer.MIN_VALUE : "+Integer.MIN_VALUE);
        System.out.println("Type : " + Integer.TYPE);
        System.out.println("Siez : " + Integer.SIZE);
    
        
        int num = i2.intValue();
        System.out.println("int num = i2.intValue();" + num); 
        
        int num2=Integer.parseInt("10"); //String>int
        num2+=1;
        System.out.println("num2 : " + num2);
        
        // String > integer , int > integer        
        Integer i3 = Integer.valueOf("10");
        int num3=i3.intValue();
        System.out.println("num3 : " + num3);
        
    }
 
}

    public static void main(String[] args) {
 
        Integer iValue=10; // autoboxing
        // Integer iValue=new Integer(10)
        // Integer iValue=Integer.valueOf(10)
        Double dValue=3.14;
        //Double dValue=new Double(3.14)
        //Double dValue=Double.valueOf(3.14)
        
        System.out.println(iValue); // iValue.toString()
        System.out.println(dValue); // dValue.toString()
        
        int num1=iValue; // Integer > int Auto unboxing
        double num2= dValue;
        
        System.out.println(num1);
        System.out.println(num2);
 
    }
 
}