Collect.js | first() Function

The first() function gives the first value of the collection. Simply means it returns the first value or the first method returns the first element in the collection that passes a given condition.  In JavaScript, the array is first converted to a collection and then the function is applied to the collection.

Syntax:

data.first(e)

Parameters:  This function accepts a single parameter as mentioned above and described below:

• e : This parameter holds a condition that has to pass by the collection

Return value: Processed value

Below examples illustrate the first() function in collect.js

Example 1: Here in this example, we take a collection and then using the first() function to get first value.

Javascript

// It is used to import collect.js library

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

const nums = [0 , 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9];
const data = collect(nums);

let value = data.first(e => e =4);
console.log(value);

Output :

0

Example 2: In this example, we will get the first negative value.

Javascript

// It is used to import collect.js library

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

const num = [0 , 1 , 2 , 3 , -4 , 5 , -6 , 7 , 8 , 9];
const data = collect(num);

let value = data.first(e => e < 0);
console.log(value);

Output: 

-4

Reference: https://collect.js.org/api/first.html