Whilst reading a comment by Mike DeBoer on Ajaxian about delimiting JavaScript strings with backslashes, I thought it’s worth mentioning it here as well, if only to remind myself.
String concatenation always creates a new string.
Thus, writing:
var str = "This is a long" +
" string. That's why we want to " +
" split it over several lines";
is slower & more memory intensive than writing:
var str = "This is a long\
string. That's why we want to\
split it over several lines";
Just be careful you don’t have trailing spaces as that will mess it up.
Tags: JavaScript, Performance
So, whats the result from the second one? I woudl expect:
var str = “This is a long string. That’s why we want to split it over several lines”;
which isn’t whats desired, right?
the slower and more memory intensive part, however, would be measured in bytes (10’s of) and maybe milliseconds – hardly enough to mess up your code’s readability for…!?
oops, formatting messed that up. Was ment to be:
var str = “This is a long(8 spaces)string. That’s why we want to(8 spaces)split it over several lines”;
You are absolutely right. I fixed the example!
As always: this doesn’t make an awful lot of difference with 1 example but across a page with numerous scripts & other things, it should be avoided, like for … in loops, etc. Don’t forget: we don’t all use Chrome, Firefox 3 & Safari 3.
Thanks for making me aware of it!