Javascript, why treated as octal

Question

I\'m passing as parameter an id to a javascript function, because it comes from UI, it\'s left zero padded. but it seems to have (maybe) \"strange\" behaviour?

Answer 1

Leading 0s indicate that the number is octal.

parseInt parses a string containing a number.
parseInt(0000022115, 10) passes a numeric literal. The literal is parsed in octal by the JS interpreter, so you're passing a raw numeric value to parseInt.