concat in javascript code example

Example 1: combine two arrays javascript

let arr1 = [0, 1, 2];
let arr2 = [3, 5, 7];
let primes = arr1.concat(arr2);

// > [0, 1, 2, 3, 5, 7]

Example 2: string concatenation in js

var str1 = "Hello ";
var str2 = "world!";
var res = str1.concat(str2);
console.log(res);

Example 3: javascript concat two arrays

//ES6
const array3 = [...array1, ...array2];

Example 4: how to concatenate strings javascript

var str1 = "Hello ";
var str2 = "world!";
var res = str1.concat(str2);
// does not change the existing strings, but
// returns a new string containing the text
// of the joined strings.

Example 5: javascript concat

let chocholates = ['Mars', 'BarOne', 'Tex'];
let chips = ['Doritos', 'Lays', 'Simba'];
let sweets = ['JellyTots'];

let snacks = [];
snacks.concat(chocholates);
// snacks will now be ['Mars', 'BarOne', 'Tex']
// Similarly if we left the snacks array empty and used the following
snacks.concat(chocolates, chips, sweets);
//This would return the snacks array with all other arrays combined together
// ['Mars', 'BarOne', 'Tex', 'Doritos', 'Lays', 'Simba', 'JellyTots']

Example 6: string concat javascript

//This method adds two or more strings and returns a new single string.

let str1 = new String( "This is string one" ); 
let str2 = new String( "This is string two" ); 
let str3 = str1.concat(str2.toString());
console.log("str1 + str2 : "+str3)

output:
str1 + str2 : This is string oneThis is string two