Javascript parseInt gives very unexpected results [duplicate]

Answer 1

It sounds like your date is being parsed as hex - the leading zero is doing this.

Because the hex and decimal representations are the same for 0-7 it 'works', but 8 and 9 get incorrectly converted.

Use

parseInt(date[1], 10)

To specify the base explicitly.

Answer 2

That's because numbers that start with 0 are treated as octal numbers and "08" is not an octal so 0 is returned.

Read this: http://mir.aculo.us/2010/05/12/adventures-in-javascript-number-parsing/

Answer 3

Use

parseInt(date[1], 10)

to make sure the string is interpreted as base 10 (decimal).

Otherwise, it is interpreted as base 8 (octal) if it starts with "0", or as base 16 (hexadecimal) if it starts with "0x".

In fact, you should always include the base argument to avoid these kinds of bugs.

Answer 4

The parseInt() function has the second optional radix parameter. If the radix parameter is omitted, JavaScript assumes the following:

• If the string begins with "0x", the radix is 16 (hexadecimal)
• If the string begins with "0", the radix is 8 (octal). This feature is deprecated
• If the string begins with any other value, the radix is 10 (decimal)

So in your case it assumes the octal numbers. Change to var MM = parseInt(date[1], 10); and it will work