Why Does Parseint("09") Return 0 But Parseint("07") Return 7?

Possible Duplicate: Workarounds for JavaScript parseInt octal bug Why does parseInt('09') return 0 but parseInt('07') return 7?

Solution 1:

The base for strings starting with 0 can be octal (when a radix is not specified - and depending on the browser).

You are looking for:

parseInt("09", 10)

See the documentation for parseInt:

If radix is undefined or 0, JavaScript assumes the following:

• If the input string begins with "0x" or "0X", radix is 16 (hexadecimal).
• If the input string begins with "0", radix is eight (octal). This feature is non-standard, and some implementations deliberately do not support it (instead using the radix 10). For this reason always specify a radix when using parseInt.
• If the input string begins with any other value, the radix is 10 (decimal).

The comments for the radix optional parameter (the second one in my example) says this:

While this parameter is optional, always specify it to eliminate reader confusion and to guarantee predictable behavior.

Solution 2:

A leading 0 indicated an coal value "020" is 16, "07" is 7, there is no digit "9" in the octal system, hence no conversion!

Use parseInt("09", 10) to get the value 9.