Lodash _.not() Method

The Lodash _.not() method returns a boolean value which is the opposite of the truthiness boolean value of the given value.

Syntax:

_.not( value );

Parameters: This method takes one parameter as mentioned above and described below:

• 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 lodash.js contrib library to be installed. Lodash.js contrib library can be installed using npm install lodash-contrib –save.

Example 1:

Javascript

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

var bool = _.not( true );

console.log("Opposite boolean value 'true' is : ", bool);

var bool = _.not( false );

console.log("Opposite boolean value 'false' is : ", bool);

Output:

Opposite boolean value 'true' is : false
Opposite boolean value 'false' is : true

Example 2:

Javascript

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

var bool = _.not( 0 );

console.log("Opposite boolean value '0' is : ", bool);

var bool = _.not( 1 );

console.log("Opposite boolean value '1' is : ", bool);

var bool = _.not( 10 );

console.log("Opposite boolean value '10' is : ", bool);

Output:

Opposite boolean value '0' is : true
Opposite boolean value '1' is : false
Opposite boolean value '10' is : false

Example 3:

Javascript

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

var bool = _.not( {} );

console.log("Opposite boolean value empty object is : ", bool);

var bool = _.not( {'G' : "GeeksforGeeks"} );

console.log("Opposite boolean value object is : ", bool);

var bool = _.not( null );

console.log("Opposite boolean value 'null' is : ", bool);

Output:

Opposite boolean value empty object is : false
Opposite boolean value object is : false
Opposite boolean value 'null' is : true