Repeat a string in JavaScript a number of times

Question

In Perl I can repeat a character multiple times using the syntax:

$a = "a" x 10; // results in "aaaaaaaaaa" 

Is there a simple way to accomplish this in Javascript? I can obviously use a function, but I was wondering if there was any built in approach, or some other clever technique.

Answer 1

These days, the repeat string method is implemented almost everywhere. (It is not in Internet Explorer.) So unless you need to support older browsers, you can simply write:

"a".repeat(10) 

Before repeat, we used this hack:

Array(11).join("a") // create string with 10 a's: "aaaaaaaaaa" 

(Note that an array of length 11 gets you only 10 "a"s, since Array.join puts the argument between the array elements.)

Simon also points out that according to this benchmark, it appears that it's faster in Safari and Chrome (but not Firefox) to repeat a character multiple times by simply appending using a for loop (although a bit less concise).