Java Foundation-logical operator Logic Operators

Java Foundation-logical operator Logic Operators

Yun Zhengjie

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I. Logical operators

Logical operators operate on Boolean values, which are common:

1> logic and (&);

2> logical OR (|);

3>. Logical XOR (^);

4>. logical non (!);

5>: Short circuit and (&&);

6> Short circuit or (| | ）；

The following rules are summarized:

1>. " & ": Only two operands are true, the result is true, the rest is false;
2>. "|" : As long as one operand is true, the result is true and the rest is false;
3>. "! ": Inverse, true changes false,false to true;
4>. Only one of the single operands;
5> The meaning of XOR: To make a difference, only two operands are different, the entire expression is true;

Two. Case Show

1>: Operands and Boolean values for logical operators

1 /*2 @author: Yinzhengjie3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Java%E5%9F%BA%E7%A1%80/4 Email:[email protected]5 */6 7  Public classlogicdome{8      Public Static voidMain (string[] args) {9         Ten         //operands and Boolean values for logical operators OneSystem.out.println (true&true);//true ASystem.out.println (false|true);//true -System.out.println (true^false);//true -System.out.println (true^true);//false theSYSTEM.OUT.PRINTLN (!true);//false -SYSTEM.OUT.PRINTLN (!false);//true -          -     } +}

2>: Short circuit and &&, operation result same as Logic & (recommended)

1 /*2 @author: Yinzhengjie3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Java%E5%9F%BA%E7%A1%80/4 Email:[email protected]5 */6 7  Public classlogicdome2{8      Public Static voidMain (string[] args) {9         Ten         //Short Circuit and &&, operation result is same as logic & One         intnum = 2018; ASYSTEM.OUT.PRINTLN (num < 0) & (++num > 0));//false -SYSTEM.OUT.PRINTLN (num);//2019 -          the         //short-circuit and && If the left expression is false, the value of the right expression is not evaluated -num = 18; -SYSTEM.OUT.PRINTLN (num < 0) && (++num > 0));//false -SYSTEM.OUT.PRINTLN (num);// - +     } -}

3> short-circuit or | |, if the left is true, the value of the right expression is not evaluated (recommended)

1 /*2 @author: Yinzhengjie3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Java%E5%9F%BA%E7%A1%80/4 Email:[email protected]5 */6 7  Public classlogicdome3{8      Public Static voidMain (string[] args) {9         Ten         //short-circuit with | |, if the left is true, the value of the right expression is not evaluated One         intnum = 2018; ASYSTEM.OUT.PRINTLN (num > 0) | | (++num > 0));//false -SYSTEM.OUT.PRINTLN (num);//2018 -          the     } -}

4>: Logical operators are often used to link multiple Boolean expressions

1 /*2 @author: Yinzhengjie3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Java%E5%9F%BA%E7%A1%80/4 Email:[email protected]5 */6 7  Public classlogicdome4{8      Public Static voidMain (string[] args) {9         Ten         //logical operators are often used to link multiple Boolean expressions One         intYear = 2018;  A  -         /** - determine whether a year is a leap years: the can be divisible by 4 but not divisible by 100 | | Can be divisible by 400 directly . - (Can be divisible by 4 && not divisible by 100) | | Can be divisible by 400 directly . - (year%4==0 && year%100!=0) | | year%400==0; -         */ +          -         BooleanIsPrime = (year%4==0 && year%100!=0) | | year%400==0;//false +      A System.out.println (isprime); at          -     } -}

Java Foundation-logical operator Logic Operators