If-Else-If Statement

In JavaScript, if-else-if statement is used to execute a ladder of conditional code.

Syntax

if (condition1) {
  //code
} else if (condition2) {
  //code
} else if (condition3) {
  //code
} else {
  //code
}

where

if, else are keywords.
condition1, condition2, condition3,… are boolean expressions.
code is any valid JavaScript code.

Any number of else if blocks are allowed.

else block is optional.

If condition1 is true, then if-block code is run. If condition1 is false, and condition2 is true, then first else-if-block code is run. If condition2 is also false, and condition3 is true, then second else-if-block code is run. If no condition is true, then else-block code is run.

Examples

1. In the following program, we write an if-else-if statement to check if value in a is positive, negative, or zero.

a = 10;

if (a > 0) {
  console.log("a is positive.");
} else if (a < 0) {
  console.log("a is negative.");
} else {
  console.log("a is zero.");
}

2. In the following program, we write an if-else-if statement to check if value in supplies is good(>5), need more supplies(>=0), or if supplies are in deficit(<0).

supplies = 10;

if (supplies > 5) {
  console.log("Supplies are good.");
} else if (supplies >=0) {
  console.log("Need more supplies.");
} else {
  console.log("Deficit in supplies.");
}

JavaScript Code

JavaScript If-Else-If