Is the Javascript String length constant time?

Question

I\'m fairly new to JS, and realize length is considered a property. But I received a comment to not use str.length in a loop:

for (i=0; i

Answer 1

The question seems to have been well answered, but here's another 2¢ which may be helpful.

Using string.length can cause unexpected behavior in for loops if the string is overwritten by something with a different length inside the loop e.g:

var k = "abcabcabc";
for(var i=0; i

Will log "abcabcab", "abcabca", ... , "abca" and then stop because the length is changing.

Of course, this may be intentional, in which case go for it (although arguably you should use a while loop).