prepend a string javascript code example

Example 1: how to concatenate strings and variables in javascript

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

Example 2: 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]

Example 3: string concatenation js

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