how to add value in string javascript 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: javascript add to string

var s = 'hell'
s = s + 'o'

Example 5: string concatenation js

var aString="";
aString.concat(value1, value2, ... value_n);