hljs.highlightAll();

Logical Operators in JavaScript

Introduction

Logical operators are used to make decisions in JavaScript programming. They allow you to combine multiple conditions together to form a single expression. The && operator is one of the logical operators in JavaScript.

Explanation of the && Operator

The && operator is also known as the logical AND operator. It returns true if both operands are true, and false otherwise.

		var x = 5;
		var y = 10;
		if (x < 10 && y > 5) {
			console.log("Both conditions are true.");
		}
		// Output: Both conditions are true.
	

Explanation of the Code

• We declare two variables x and y with values 5 and 10 respectively.
• We use the if statement to check if x is less than 10 AND y is greater than 5. This is done using the && operator.
• The console.log statement is executed only if both conditions are true.

Multiple Ways to Use the && Operator

Using the && Operator with Non-Boolean Values

The && operator can also be used with non-boolean values. In this case, the operator returns the first operand if it is falsy, and the second operand otherwise.

		var x = 0;
		var y = 10;
		var result = x && y;
		console.log(result);
		// Output: 0
	

• We declare two variables x and y with values 0 and 10 respectively.
• We use the && operator to combine the two variables. In this case, since x is falsy (0 is considered falsy in JavaScript), the operator returns x (0).
• The result is assigned to a new variable result.
• The console.log statement outputs the value of result (which is 0).

Using the && Operator with Functions

The && operator can also be used with functions. In this case, the second function is executed only if the first function returns true.

		function isLoggedIn() {
			return true;
		}
		
		function displayContent() {
			console.log("Welcome to our website!");
		}
		
		isLoggedIn() && displayContent();
		// Output: Welcome to our website!
	

• We define two functions isLoggedIn and displayContent.
• The isLoggedIn function always returns true.
• We use the && operator to combine the two functions. In this case, since isLoggedIn returns true, the second function (displayContent) is executed.
• The console.log statement inside displayContent is executed, outputting "Welcome to our website!"