Chapter3. 연산자 .3 단항 연산자

[SignOperatorExample.java] 부호 연산자

package july25_chap3;

public class clon_sec03_ex1 {
	public static void main(String[] args) {
		int x = -100;
		int result1 = +x;	//+(-100) = -100
		int result2 = -x;	//-(-100) = 100
		System.out.println("result1= " + result1);
		System.out.println("result2= " + result2);
		
		short s = 100;
		//short result3 = -s;  -부호 붙이는 것도 연산이기 때문에 int 써야함
		int result3 = -s;	//-(100) = -100
		System.out.println("result3= " + result3);
	}
}
</>
result1= -100
result2= 100
result3= -100

 

[IncreaseDecreaseOperatorExample.java] 증감 연산자

package july25_chap3;

public class clon_sec03_ex2 {
	public static void main(String[] args) {
		int x = 10;
		int y = 10;
		int z;
		
		System.out.println("-----------------------");
		x++;	//뒤에 ++면, 바로 값이 변하지 않음. 변수를 가져다 쓸 때 +1이 됨 = 10
		++x;	//바로 +1 = x는 11에서 +1 = 12
		System.out.println("x= " + x);
		
		System.out.println("-----------------------");
		y--;	//y = 10
		--y;	//y = 9 -1 = 8
		System.out.println("y= " + y);
		
		System.out.println("-----------------------");
		z = x++;	//z = 12
		System.out.println("z= " + z);	//z=12
		System.out.println("x= " + x);	//x =12+1 = 13
		
		System.out.println("-----------------------");
		z = ++x;	//z=13+1
		System.out.println("z= " + z);	//z = 14
		System.out.println("x= " + x);	//x = 14
		
		System.out.println("-----------------------");
		z = ++x + y++;	//z = (14+1) + 8 = 23
		System.out.println("z= " + z);	//z = 23
		System.out.println("x= " + x);	//x = 15
		System.out.println("y= " + y);	//y = 9
	}
}
</>
-----------------------
x= 12
-----------------------
y= 8
-----------------------
z= 12
x= 13
-----------------------
z= 14
x= 14
-----------------------
z= 23
x= 15
y= 9

 

[DenyLogicOperatorExample.java] 논리 부정 연산자

package july25_chap3;

public class clon_sec03_ex3 {
	public static void main(String[] args) {
		
		boolean play = true;
		System.out.println(play);	//true
		
		play = !play;	//true의 반대
		System.out.println(play);
		
		play = !play;	//false의 반대
		System.out.println(play);
	}
}

</>
true
false
true

 

[BitReverseOperatorExample.java] 비트 반전 연산자

package july25_chap3;

public class clon_sec03_ex4 {
	public static void main(String[] args) {
		int v1 = 10;
		int v2 = ~v1;
		int v3 = ~v1 + 1;
		System.out.println(toBinaryString(v1) + " (십진수: " + v1 + ")");
		System.out.println(toBinaryString(v2) + " (십진수: " + v2 + ")");
		System.out.println(toBinaryString(v3) + " (십진수: " + v3 + ")");
		System.out.println();
		
		int v4 = -10;
		int v5 = ~v4;
		int v6 = ~v4 + 1;
		System.out.println(toBinaryString(v4) + " (십진수: " + v4 + ")");
		System.out.println(toBinaryString(v5) + " (십진수: " + v5 + ")");
		System.out.println(toBinaryString(v6) + " (십진수: " + v6 + ")");	
	}
	
	public static String toBinaryString(int value) {
		String str = Integer.toBinaryString(value);
		while(str.length() < 32) {
			str = "0" + str;
		}
		return str;
	}
}


//10진수를 2진수로 바꾸는 법
//int v1 = 10
//32비트 = 00000000 00000000 00000000 00000000 = 0
//32비트 = 00000000 00000000 00000000 00001010 = 10

</>
00000000000000000000000000001010 (십진수: 10)
11111111111111111111111111110101 (십진수: -11)
11111111111111111111111111110110 (십진수: -10)

11111111111111111111111111110110 (십진수: -10)
00000000000000000000000000001001 (십진수: 9)
00000000000000000000000000001010 (십진수: 10)