JavaScript - Conditional or Ternary operator (?:)

The JavaScript conditional or ternary operator returns one of the two values based on the value of boolean expression. It is kind of similar to the if-else statement and helps to write the if-else statements in a short way.

Syntax

//returns value1 if expression is true
//returns value2 if expression is false
expression ? value1 : value2

Return Value

Returns value1 if the expression is evaluated to be true, and value2 if the expression is evaluated to be false.

Example:

In the example below, the ternary operator is used to find out the maximum of two numbers.

var x = 50;
var y = 100;
var txt;

//maximum of two value
var max = (x > y) ? x : y;
txt = "Maximum value = " + max;

The output (value of txt) after running above script will be:

Maximum value = 100

Example:

In the example below, the ternary operator is used to perform time-based greeting.

var hour = new Date().getHours();
var greeting;

//time-based gretting
greeting = (hour < 18) ? "Good Day!" : "Good Evening";

The output (value of greeting) after running above script will be: