The _.isWeakMap() method is used to find whether the given value is a weakmap object or not. It returns True if the given value is a weakmap object. Otherwise, it returns false.
Syntax:
_.isWeakMap(value)
Parameters: This method accepts a single parameter as mentioned above and described below:
-
value: This parameter holds the value to check.
Return Value: This method returns true if value is a weakmap, else false.
Note: Here, const _ = require(‘lodash’) is used to import the lodash library into the file.
Example 1:
// Requiring the lodash library const _ = require( "lodash" ); // Creating a array of size 2 // using constructor var obj= new Array(2); // Filling value 5 in the array obj.fill(5) // Use of _.isWeakMap() method console.log(_.isWeakMap(obj)); |
Output:
false
Example 2:
// Requiring the lodash library const _ = require( "lodash" ); // Use of _.isWeakMap() method // When a weak set is given console.log(_.isWeakMap( new WeakMap)); // When a weak set is not given console.log(_.isWeakMap( new Map)); |
Output:
true false
Note: This will not work in normal JavaScript because it requires the library lodash to be installed.
Reference: https://lodash.com/docs/4.17.15#isWeakMap