Java SE(23) operator-logical operator

table of Contents

Logical Operators

&和&&

|and||

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Logical Operators

Logical operators are used to operate on Boolean data , and the result is still a Boolean data .

Operator	Calculation	example	result
&	versus	true&true	true
		true&false	false
		false&true	true
		false&false	false
&&	Short circuit with	true&true	true
		true&false	false
		false&true	true
		false&false	false
|	or	true | true	true
		true | false	true
		false | true	true
		false | false	false
||	Short circuit or	true || true	true
		true || false	true
		false || true	true
		false || false	false
^	XOR	true^true	false
		true^false	true
		false^true	true
		false ^ false	false
!	non-	!true	false
		!false	true

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Exercise:

public class TestOpe11{
	public static void main(String[] args){
		//逻辑与：&   规律：全对为对。
		System.out.println(true&true);     //true
		System.out.println(true&false);    //false
		System.out.println(false&true);    //false
		System.out.println(false&false);   //false
		//短路与：&&  规律：全对为对
		//只要左边表达式是false，右边的表达式不会进行运算，结果为false。
		System.out.println(true&&true);     //true
		System.out.println(true&&false);    //false
		System.out.println(false&&true);    //false
		System.out.println(false&&false);   //false
		
		//逻辑或：|   规律：任一为true，结果为true。
		System.out.println(true|true);     //true
		System.out.println(true|false);    //true
		System.out.println(false|true);    //true
		System.out.println(false|false);   //false
		//短路或：||  规律：任一为true，结果为true。
		//只要左边表达式是true，右边的表达式不会进行运算，结果为true。
		System.out.println(true||true);     //true
		System.out.println(true||false);    //true
		System.out.println(false||true);    //true
		System.out.println(false||false);   //false
		
		//逻辑异或：^  规律：运算符两边的布尔值不同时，结果为true。
		System.out.println(true^true);     //false
		System.out.println(true^false);    //true
		System.out.println(false^true);    //true
		System.out.println(false^false);   //false
		
		//逻辑非：!    规律：相反结果。
		System.out.println(!true);       //false
        System.out.println(!false);      //true
	}
}

 operation result:

  

• &和&&

       The same point : & operator && expressed and operation , if and only if the operand on both sides of the operator are true , its result it is true , otherwise the result is false.

       Difference : When using & to calculate, no matter if the left side is true or false, the expression on the right will be calculated .

                     If && is used for calculation, when the left side is false , the expression on the right will not be calculated , so && is called a short-circuit and.

Exercise: 

public class TestOpe12{
	public static void main(String[] args){
		//左边为false
		int a=8;
		System.out.println((5>7)&(a++==2));   //false
		System.out.println("a="+a);       //i=9
		
		int b=8;
		System.out.println((5>7)&&(b++==2));   //false
		System.out.println("b="+b);       //左边表达式为flase，右边表达式不进行运输算 i=8
		
		//左边为true
		int m=8;
		System.out.println((5<7)&(m++==2));   //false
		System.out.println("m="+m);       //i=9
		
		int n=8;
		System.out.println((5<7)&&(n++==2));   //false
		System.out.println("n="+n);       //i=9
		
	}
}

  operation result:

  

• |and||

       The same point : Operator | and || expressed or operation , and if the operand on both sides of operators on either side of the value is true , its result it is true , when the value of both sides are fals time E, the result is false .

       Difference : When using | for calculation, the expression on the right will be calculated regardless of whether the left side is true or false .

                     If you use || for calculation, when the left side is true , the expression on the right will not be calculated , so || is called a short-circuit or.