Underscore.js _.isIndexed() Method

The _.isIndexed() method checks whether the given value can be considered “Indexed” or not and returns the corresponding boolean value. Indexed value is one that accepts a numerical index to access its elements.

Syntax:

_.isIndexed( value );

Parameters: 

  • value: Given value to be checked for Indexed value.

Return Value: This method returns a Boolean value(Returns true if the given value is Indexed, else false).

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 .



Example 1: An array can be considered as Indexed value and its elements can be accessed using numerical indexes.

Javascript

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// Defining underscore contrib variable
var _ = require('underscore-contrib'); 
  
// Checking
console.log("The Value is Indexed : " 
    + _.isIndexed([1, 3, 5]));

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Output:

The Value is Indexed : true

Example 2: This method returns false for a mapping.

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// Defining underscore contrib variable
var _ = require('underscore-contrib'); 
  
// Checking
console.log("The Value is Indexed : " 
    + _.isIndexed({1:3, 2:3}));

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Output:

The Value is Indexed : false

Example 3: For a string, this method returns true.

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// Defining underscore contrib variable
var _ = require('underscore-contrib'); 
  
// Checking
console.log("The Value is Indexed : " 
    + _.isIndexed("GeeksforGeeks"));

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Output:

The Value is Indexed : true

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