How can I split a string into segments of n characters?

Question

var str="abcdefghijkl";
console.log(str.match(/.{1,3}/g));

Note: Use {1,3} instead of just {3} to include the remainder for string lengths that aren’t a multiple of 3, e.g:

console.log("abcd".match(/.{1,3}/g)); // ["abc", "d"]

A couple more subtleties:

If your string may contain newlines (which you want to count as a character rather than splitting the string), then the . won’t capture those. Use /[\s\S]{1,3}/ instead. (Thanks @Mike).
If your string is empty, then match() will return null when you may be expecting an empty array. Protect against this by appending || [].

So you may end up with:

var str="abcdef \t\r\nghijkl";
var parts = str.match(/[\s\S]{1,3}/g) || [];
console.log(parts);

console.log(''.match(/[\s\S]{1,3}/g) || []);