The _.not() method returns a boolean value which is the opposite of the truthiness boolean value of the given value.
Syntax:
_.not( value );
Parameters:
- value: Given value for returning opposite boolean.
Return Value: This method returns a Boolean value.
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: It returns false for this method.
Javascript
// Defining underscore contrib variable var _ = require( 'underscore-contrib' ); var bool = _.not( true ); console.log( "Opposite boolean value if" + " value's truthiness is : " , bool); |
Output:
Opposite boolean value if value's truthiness is : false
Example 2: For false, this method returns opposite value that is true.
Javascript
// Defining underscore contrib variable var _ = require( 'underscore-contrib' ); var bool = _.not( false ); console.log( "Opposite boolean value if" + " value's truthiness is : " , bool); |
Output:
Opposite boolean value if value's truthiness is : true
Example 3: For existing values, this method returns false.
Javascript
// Defining underscore contrib variable var _ = require( 'underscore-contrib' ); var bool = _.not( "Geeks" ); console.log( "Opposite boolean value if" + " value's truthiness is : " ,bool); |
Output:
Opposite boolean value if value's truthiness is : false
Example 4: for non-existing values, this method returns true.
Javascript
// Defining underscore contrib variable var _ = require( 'underscore-contrib' ); var bool = _.not( null ); console.log( "Opposite boolean value if" + " value's truthiness is : " , bool); |
Output:
Opposite boolean value if value's truthiness is : true