Underscore.js _.kv() Method

The _.kv() method returns the key/value pair for a given property in an object, returns undefined if not found.

Syntax:

_.kv( Object_name, property );

Parameters:

• Object_name: Object from which the key/value pair is to be searched.
• property: Given the property of which given key/value pair is to be searched.

Return Value: This method returns the key/value pair for a given property.

Note: This will not work in normal JavaScript because it requires the underscore.js contrib library to be installed. 

Underscore.js contrib library can be installed using npm install underscore-contrib –save.

Example 1:

Javascript

// Defining underscore contrib variable
var _ = require('underscore-contrib');

var ob = { "gfg" : "GeeksforGeeks" };
var val = _.kv( ob, "gfg");

console.log(val);

Output:

[ 'gfg', 'GeeksforGeeks' ]

Example 2: if no key/value is found, this method returns undefined.

Javascript

// Defining underscore contrib variable
var _ = require('underscore-contrib');

var ob = { "gfg" : "GeeksforGeeks" };
var val = _.kv( ob, "geek");

console.log(val);

Output:

undefined