Lodash _.partition() Method

Lodash _.partition() method creates an array of elements split into two groups, the first of which contains elements predicate returns true and the second of which contains elements predicate returns false.

Syntax:

_.partition(collection, predicate);

Parameters:

• collection (Array|Object) parameter holds the collection to iterate over.
• predicate (Function) parameter holds the function invoked per iteration and is invoked with one argument (value).

Return Value:

This method returns the array of grouped elements.

Example 1: In this example, we are partitioning our array into two parts one which has true as an active value and another is false as an active value.

javascript

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

// Original array
let users = [
    { 'customer': 'john', 'age': 26, 'active': false },
    { 'customer': 'jonny', 'age': 34, 'active': true },
    { 'customer': 'johnson', 'age': 12, 'active': false }
];

// Use of _.partition() method

let gfg = _.partition(users,
    function (o) { return o.active; });

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

Output:

[
  [ { customer: 'jonny', age: 34, active: true } ],
  [
    { customer: 'john', age: 26, active: false },
    { customer: 'johnson', age: 12, active: false }
  ]
]

Example 2: In this example, we are partitioning our array into two parts. we are passing our condition as an object into the _.partitiion() method.

javascript

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

// Original array
let users = [
    { 'customer': 'john', 'age': 26, 'active': false },
    { 'customer': 'jonny', 'age': 34, 'active': true },
    { 'customer': 'johnson', 'age': 12, 'active': false }
];

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

let gfg = _.partition(users, {
    'age': 12, 'active': false
});

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

Output:

[
  [ { customer: 'johnson', age: 12, active: false } ],
  [
    { customer: 'john', age: 26, active: false },
    { customer: 'jonny', age: 34, active: true }
  ]
]

Example 3: In this example, we are partitioning our array into two parts. we are passing our condition as an array into the _.partitiion() method.

javascript

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

// Original array
let users = [
    { 'customer': 'john', 'age': 26, 'active': false },
    { 'customer': 'jonny', 'age': 34, 'active': true },
    { 'customer': 'johnson', 'age': 12, 'active': false }
];

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

let gfg = _.partition(users, ['active', false]);

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

Output:

[
  [
    { customer: 'john', age: 26, active: false },
    { customer: 'johnson', age: 12, active: false }
  ],
  [ { customer: 'jonny', age: 34, active: true } ]
]