Collect.js when() Method

The when() method is used to execute the given callback when the first argument given to the method evaluates to true.

Syntax:

collect.when()

Parameters: The collect() method takes one argument that is converted into the collection and then when() method is applied on it.

Return Value: This method returns the merged collection elements.

Below example illustrate when() method in collect.js:

Example 1:

Javascript

const collect = require('collect.js');

let arr = ['C++', 'java', 'python'];

const collection = collect(arr);

collection.when(true, items => items.push('c#'));

let newObject =  collection.all();

console.log(newObject);

Output:

["C++", "java", "python", "c#"]

Example 2:

Javascript

const collect = require('collect.js');

let arr = [1, 2, 3, 4];

const collection = collect(arr);

collection.when(true, items => items.push(5, 6, 7));

let newObject =  collection.all();

console.log(newObject);

Output:

[1, 2, 3, 4, 5, 6, 7]