Lodash _.concat() Function

Lodash proves to be much useful when working with arrays, strings, objects etc. It makes math operations and function paradigm much easier, concise. The _.concat() function is used to concatenating the arrays in JavaScript.

Syntax:

_.concat(array, [values])

Parameters: This function accept two parameters as mentioned above and described below: 

• array: It is an array to which values are to be added.
• values: It is the Array of values that is to be added to the original array.

Note: The array value can also contain arrays of array or simple a single object to be added to original array.

Return Value: This function returns the array after concatenation.

Few examples are given below for better understanding of the function.

Example 1:

Javascript

// Requiring the lodash library
let lodash = require("lodash");

// Original array to be concatenated
let array = [1, 2, 3];

// Values to be added to original array
let values = [0, 5, "a", "b"]

let newArray = lodash.concat(array, values);
console.log("Before concat: " + array);

// Printing newArray
console.log("After concat: " + newArray);

Output:

Example 2: Adding array of array to original array.

JavaScript

// Requiring the lodash library
let lodash = require("lodash");

// Original array to be concatenated
let array = ["a", 2, 3];

// Array of array to be added
// to original array
let values = [0, 5, ["a", "b"]]
let newArray = lodash.concat(array, values);
console.log("Before concat: ", array);

// Printing array
console.log("After concat: ", newArray);

Output:

Example 3: This example adding the object to the array.

Javascript

// Requiring the lodash library
let lodash = require("lodash");

// Original array to be concatenated
let array = ["a", 2, 3];

// Object of values to be
// added to original array
let values = { "a": 1, "b": 2 }
let newArray = lodash.concat(array, values);
console.log("Before concat: ", array);

// Printing array
console.log("After concat: ", newArray);

Output: