The _.taketWhile the method is used to create a slice of an array in which elements are taken from the beginning. Also, these elements are taken until predicate returns falsely.
Syntax:
_.takeWhile(array, [predicate=_.identity])
Parameters: This method accepts two parameters as mentioned above and described below:
- array: This parameter holds the array to query.
- [predicate=_.identity]: This parameter holds the function invoked per iteration.
Return Value: This method is used to return the slice of array.
Example 1: Here, const _ = require(‘lodash’) is used to import the lodash library in the file.
javascript
// Requiring the lodash library const _ = require( "lodash" ); // Original array var users = [ { 'user' : 'jupiter' , 'active' : false }, { 'user' : 'mercury' , 'active' : false }, { 'user' : 'saturn' , 'active' : true } ]; // Use of _.takeWhile() // method let gfg = _.takeWhile(users, function (o) { return !o.active; }); // Printing the output console.log(gfg); |
Output:
[{ user: 'jupiter', active: false }, {user: 'mercury', active: false}]
Example 2:
javascript
// Requiring the lodash library const _ = require( "lodash" ); // Original array var users = [ { 'user' : 'jupiter' , 'active' : false }, { 'user' : 'mercury' , 'active' : false }, { 'user' : 'saturn' , 'active' : true } ]; // Use of _.takeWhile() // method // The `_.matches` iteratee shorthand. let gfg = _.takeWhile(users, { 'user' : 'jupiter' , 'active' : false }); // Printing the output console.log(gfg); |
Output:
[{ user: 'jupiter', active: false }]
Example 3:
javascript
// Requiring the lodash library const _ = require( "lodash" ); // Original array var users = [ { 'user' : 'jupiter' , 'active' : false }, { 'user' : 'mercury' , 'active' : false }, { 'user' : 'saturn' , 'active' : true } ]; // Use of _.takeWhile() // method // The `_.matchesProperty` iteratee shorthand. let gfg = _.takeWhile(users, [ 'active' , false ]); // Printing the output console.log(gfg); |
Output:
[{ user: 'jupiter', active: false }, {user: 'mercury', active: false}]
Example 4:
javascript
// Requiring the lodash library const _ = require( "lodash" ); // Original array var users = [ { 'user' : 'jupiter' , 'active' : false }, { 'user' : 'mercury' , 'active' : false }, { 'user' : 'saturn' , 'active' : true } ]; // Use of _.takeWhile() // method // The `_.property` iteratee shorthand. let gfg = _.takeWhile(users, 'active' ); // Printing the output console.log(gfg); |
Output:
[]
Note: This code will not work in normal JavaScript because it requires the library lodash to be installed.
Whether you’re preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, neveropen Courses are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we’ve already empowered, and we’re here to do the same for you. Don’t miss out – check it out now!