my code:

var test = "aa";
test += "ee";
alert(test); 

Prints out "aaee"

How can I do the same thing, but add the string not to end, but start: Like this:

var test = "aa";
test = "ee" + test;

This is the long way, but is there somekind of shorter way like in 1st example?

What I want is that I must not write the initial variable out again in definition.

my code:

var test = "aa";
test += "ee";
alert(test); 

Prints out "aaee"

How can I do the same thing, but add the string not to end, but start: Like this:

var test = "aa";
test = "ee" + test;

This is the long way, but is there somekind of shorter way like in 1st example?

What I want is that I must not write the initial variable out again in definition.

• javascript
• string

• Your two code samples are not the same. The first yields "aaee" the second "eeaa"; – The Internet Commented Aug 23, 2012 at 6:46
• @Dave thats what I want to do, read the bold :P – Jaanus Commented Aug 23, 2012 at 6:47
• jQuery offers a .prepend() function. In pure JS I would just do test += "ee"; Also, why do you want to do this? – The Internet Commented Aug 23, 2012 at 6:48

6 Answers 6

There's no built-in operator that allows you to achieve this as in the first example. Also test = "ee" + test; seems pretty self explanatory.

You could do it this way ..

test = test.replace (/^/,'ee');

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

You have a few possibilities although not a really short one:

var test = "aa";

// all yield eeaa
result = "ee" + test;
result = test.replace(/^/, "ee");

var test = "aa";
 alert('ee'.concat(test));

What you have, test = "ee" + test; seems completely fine, and there's no shorter way to do this.

If you want a js solution on this you can do something like,

test = test.replace(/^/, "ee");

There are a whole lot of ways you can achieve this, but test = "ee" + test; seems the best imo.

You can add a string at the start (multiple times, if needed) until the resulting string reaches the length you want with String.prototype.padStart(). like this:

var test = "aa";
test = test.padStart(4, "e");
alert(test);

Prints out

eeaa

var test = "aa";
test = test.padStart(5, "e");
alert(test);

Prints out

eeeaa