Underscore.JS - isUndefined method

Syntax

_.isUndefined(object)

isUndefined method checks if object is isUndefined. See the below example −

Example

var _ = require('underscore');

var value;
//Example 1: Check if argument passed is undefined
console.log(_.isUndefined(value));

value = 0;
//Example 2: Check if argument passed is not undefined
console.log(_.isUndefined(value));

Save the above program in tester.js. Run the following command to execute this program.

Command

\>node tester.js

Output

true
false