[yread]

   > parseInt("0123Test")
   123
   > 0123
   83

parseInt is actually the adult in the room

[TeMPOraL]

In a way. The convention is that 0123 is "123" in octal.

[yread]

Yes, I know that's why I even tried it in console as I was a bit surprised that parseInt doesn't do octal.

Why does js even support octal? I never found octal particularly useful. Speak hexadecimal or die

[sweeneyrod]

Because C does.

[hurflmurfl]

    > parseInt('0123Test', 8)
    83

you could do it like this, otherwise it uses the default value for the base parameter.