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JavaScript JavaScript Foundations Numbers Parsing Numbers From Strings

Parsing Numbers From Strings

I keep getting 12 instead of 10. I am kind of lost

var j = parseInt("012");

2 Answers

Ian Svoboda
Ian Svoboda
16,639 Points

If you're trying to return 10 from that snippet, you'd need to pass in the radix (8) after your number:

var j = parseInt("012",8);

source: http://www.w3schools.com/jsref/jsref_parseint.asp

Syntax parseInt(string,radix) Parameter Values Parameter Description string Required. The string to be parsed radix Optional. A number (from 2 to 36) that represents the numeral system to be used

Thank you for the reply! :)

Dave McFarland
Dave McFarland
Treehouse Teacher

There's a teacher's note that was added after the video was created:

Please note that newer browsers will return 12 for parseInt("012") and not 10. This is because the default second parameter is now 10 for decimal instead of 8 for octal. Always specify the base if you're parsing a string to maximize compatibility.

parseInt("012", 10); // For decimal. Returns 12
parseInt("012", 8); //For octal. Returns 10