how to concatenate two strings in js code example

Example 1: string concatenation in js

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

Example 2: 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 3: how to concatenate strings and variables in javascript

const helloName = name => `Hello ${name}!`

Example 4: string javascript concatenation

var dest = new String("");
    var src = new String("aze");
    var ar = new Array();
    ...
    ar.push(src);
    ar.push(src);
    ...
    dest = ar.join("");

Example 5: how the concat function works javascript

var arr = [1, 2, 3, 4];
var arr2 = [5, 6, 7, 8];

const both = arr.concat(arr2);

console.log(both);
//[1, 2, 3, 4, 5, 6, 7, 8]