Prepend text to beginning of string

Question

What is the fastest method, to add a new value at the beginning of a string?

Answer 1

var mystr = "Doe";
mystr = "John " + mystr;

Wouldn't this work for you?

Answer 2

You could do it this way ..

var mystr = 'is my name.';
mystr = mystr.replace (/^/,'John ');

console.log(mystr);

disclaimer: http://xkcd.com/208/

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Answer 3

ES6:

let after = 'something after';
let text = `before text ${after}`;

Answer 4

you could also do it this way

"".concat("x","y")

Answer 5

Since the question is about what is the fastest method, I thought I'd throw up add some perf metrics.

TL;DR The winner, by a wide margin, is the + operator, and please never use regex

https://jsperf.com/prepend-text-to-string/1

Answer 6

If you want to use the new version of Javascript called ES 2015 (aka ES6), you could use Template strings introduced by ES 2015 and thus recommended by some guidelines (as airbnb's one) :

const after = `This is : ${after}`;

Answer 7

Another option would be to use join

var mystr = "Matayoshi";
mystr = ["Mariano", mystr].join(' ');

Answer 8

You can use

var mystr = "Doe";
mystr = "John " + mystr;
console.log(mystr)