JavaScript calculating length of a string

Why when I try this block of code:

var str = "1234";
alert(str.toString().lenght);

it alerts开发者_C百科 me 'undefined' ?

You misspelled length. It's "length":

str.toString().length

You don't actually need the toString() call here, though. "1234" is already a string, so str.length works as well.

correct your spelling...

alert(str.toString().lengTH);

Andrew

You have a spelling mistake in that code. It's length not lenght.

But aside from that, there's no need to call toString(). str.length is fine.

Just a typo: it's .length ;)