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Underscore.js _.isInstanceOf() Method

The _.isInstanceOf() method checks whether the given value is the instance of a given constructor or not and returns the corresponding boolean value. 

Syntax:

_.isInstanceOf(value, constructor);

Parameters: 

  • value: Given value to be checked for instance.
  • constructor: Given constructor.

Return Value: This method returns a Boolean value(Returns true if the given value is instance, 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:

Javascript




// Defining underscore contrib variable
var _ = require('underscore-contrib'); 
  
// Checking
console.log("The Value is Instance Of constructor : " 
    + _.isInstanceOf(new Date(),Date));


Output:

The Value is Instance Of constructor : true

Example 2:

Javascript




// Defining underscore contrib variable
var _ = require('underscore-contrib'); 
  
// Checking
console.log("The Value is Instance Of constructor : " 
    + _.isInstanceOf("abc",Date));


Output:

The Value is Instance Of constructor : false
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