Lodash _.every() Method

Lodash _.every() method checks if the predicate returns true for all elements of the collection and iteration is stopped once the predicate returns falsely.

Note: Also this method returns true for empty collections because everything is true for elements of empty collections.

Syntax:

_.every(collection, [predicate=_.identity]);

Parameters:

• collection (Array|Object): This parameter holds the collection to iterate over.
• [predicate=_.identity] (Function): This parameter holds the function invoked per iteration.

Return Value:

This method is used to return true if all elements pass the predicate check, else false.

Example 1: In this example, we are checking is every element of the given array has that data type or not and printing the result by the use of the _.every() method.

javascript

// Requiring the lodash library
const _ = require("lodash");

// Original array

let obj1 = ([true, 1, null, 'yes']);
let obj2 = ([true, 2, 'active', 'yes']);

// Use of _.every() method

let x = _.every(obj1, Boolean);
let y = _.every(obj2, Boolean);

// Printing the output
console.log(x);
console.log(y);

Output:

false
true

Example 2: In this example, we are checking is every element of the given array has that same object or not and printing the result by the use of the _.every() method.

javascript

// Requiring the lodash library
const _ = require("lodash");

// Original array

let users = [{ 'user': 'jonny', 'age': 30, 'active': false },
{ 'user': 'harry', 'age': 35, 'active': false }];

// Use of _.every() method
// The `_.matches` iteratee shorthand.

let x = _.every(users, { 'user': 'barney', 'active': false });

// Printing the output
console.log(x);

Output:

false

Example 3: In this example, we are checking is every element of the given array of objects has that same field or not and printing the result by the use of the _.every() method.

javascript

// Requiring the lodash library
const _ = require("lodash");

// Original array

let users = [
    { 'user': 'jonny', 'age': 30, 'active': false },
    { 'user': 'harry', 'age': 35, 'active': false }
];

// Use of _.every() method
// The `_.matchesProperty` iteratee shorthand.

let x = _.every(users, ['active', false]);

// Printing the output
console.log(x);

Output:

true

Example 4: In this example, we are checking is every element of the given array of objects has that string or not and printing the result by the use of the _.every() method.

javascript

// Requiring the lodash library
const _ = require("lodash");

// Original array

let users = [
    { 'user': 'jonny', 'age': 30, 'active': false },
    { 'user': 'harry', 'age': 35, 'active': false }
];

// Use of _.every() method
// The `_.property` iteratee shorthand.

let x = _.every(users, 'active');

// Printing the output
console.log(x);

Output:

false