add to a string js code example

Example 1: js concatenate strings

const str1 = 'Hello';
const str2 = 'World';

console.log(str1 + str2);
>> HelloWorld

console.log(str1 + ' ' + str2);
>> Hello World

Example 2: javascript add to string

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

Example 3: append string js

var s = "1"
s += "2"