Prepend text to beginning of string
JavascriptStringPerformanceConcatJsperfJavascript Problem Overview
What is the fastest method, to add a new value at the beginning of a string?
Javascript Solutions
Solution 1 - Javascript
var mystr = "Doe";
mystr = "John " + mystr;
Wouldn't this work for you?
Solution 2 - Javascript
You could do it this way ..
var mystr = 'is my name.';
mystr = mystr.replace (/^/,'John ');
console.log(mystr);
disclaimer: http://xkcd.com/208/
![Wait, forgot to escape a space. Wheeeeee[taptaptap]eeeeee.][1]
[1]: http://i.stack.imgur.com/zFmVi.png "Wait, forgot to escape a space. Wheeeeee[taptaptap]eeeeee."
Solution 3 - Javascript
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
Solution 4 - Javascript
ES6:
let after = 'something after';
let text = `before text ${after}`;
Solution 5 - Javascript
you could also do it this way
"".concat("x","y")
Solution 6 - Javascript
If you want to use the version of Javascript called ES 2015 (aka ES6) or later, you can use template strings introduced by ES 2015 and recommended by some guidelines (like Airbnb's style guide):
const after = "test";
const mystr = `This is: ${after}`;
Solution 7 - Javascript
Another option would be to use join
var mystr = "Matayoshi";
mystr = ["Mariano", mystr].join(' ');
Solution 8 - Javascript
You can use
var mystr = "Doe";
mystr = "John " + mystr;
console.log(mystr)