What are the three logical operators in javascript

Three logical operators in js: 1. Logical AND operator "&&", which returns true only when both operands are true; 2. Logical OR operator "||", As long as one of the two operands is true, it will return true; 3. The logical NOT operator "!" is inverted. If the operand is not true, it will return true.

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

Logical operators are usually used to combine multiple expressions. The result of a logical operator is a Boolean value, which can only have two results, either true or false. The following table lists the logical operators supported in JavaScript:

Operator	Name	Example
&&	Logical AND	x && y means if both x and y are true, then it is true
||	Logical OR	x || y means if either x or y is true, then it is true
!	Logical not	!x means if x is not true, then it is true

• Logical AND operation (&&) is an AND Boolean operation. Returns true only if both operands are true, otherwise returns false.

• Logical OR operation (||) is a Boolean OR operation. If both operands are true, or one of them is true, it returns true, otherwise it returns false.

• The logical NOT operation (!) is a Boolean negation operation (NOT). As a unary operator, it is placed directly before the operand, converts the value of the operand to a Boolean value, then inverts and returns it.

Example:

var year = 2022;
// 闰年可以被 400 整除，也可以被 4 整除，但不能被 100 整除
if((year % 400 == 0) || ((year % 100 != 0) && (year % 4 == 0))){
    console.log(year + " 年是闰年。");
} else{
    console.log(year + " 年是平年。");
}

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