if..else if..else statement in JavaScript

The if..else if..else statement in JavaScript is a conditional statement that allows you to test multiple conditions and execute different blocks of code based on those conditions.

Syntax:
The basic syntax of the if...else if...else statement is as follows:

In this syntax, condition1, condition2, condition3, etc. are expressions that can be either true or false. The if statement tests each condition in order, and the first condition that is true determines which block of code will be executed. If none of the conditions are true, the code inside the else block will be executed.

Example

Output

The above program uses the prompt function to ask the user to enter a number. The input number is stored in the number variable.

The if..else if..else statement in JavaScript then tests the value of the number variable and displays a message based on its value.

The first condition number > 0 tests if the number is greater than 0. If this condition is true, the code inside the first if block will be executed, and the message "number is a positive number." will be displayed in the console.

If the first condition is false, the second condition number < 0 tests if the number is less than 0. If this condition is true, the code inside the second else if block will be executed, and the message "number is a negative number." will be displayed in the console.

If both conditions are false, the code inside the else block will be executed, and the message "number is zero." will be displayed in the console.

This program demonstrates how to use the if..else if..else statement in JavaScript to make a simple decision based on multiple conditions and execute different blocks of code depending on the value of the input number.