Why does passing 0 to the radix of parseInt in Javascript return decimal values?

Consider the following expression

console.log( 'result: ' + parseInt("1", 0) )

It returns 1 in the console of chrome (basically returns the decimal value).

The MDN docs for parseInt says

Or NaN when the radix is smaller than 2 or bigger than 36 …

It would be great if someone could give an explanation for this.

Thanks in advance.

Answer

MDN is summarizing the specification, and is not complete.

The actual specification says:

If radix is undefined or 0, it is assumed to be 10 except when the number begins with the code unit pairs 0x or 0X, in which case a radix of 16 is assumed.