javascript concatenate two strings code example

Example 1: 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 2: string javascript concatenation

var dest = new String("");
    var src = new String("aze");
    ...
    dest += src + src + src + src + src;

Example 3: string concat in js

let string1 = "Hello"
let string2 = "World"

let finalString = string1 + ", " + string2 + "!" // Hello, World!