How does Javascript get this value?

Question

We're having a discussion in the office about how the hell this math works in JavaScript.

There was an instance where we were multiplying by 010 instead of 10 and this gave the incorrect returned value.

For example...

25.25 * 010 = 202

25.25 * 10 = 252.5 as expected

whats even weirder is if you do parseFloat(010) it gives you 8!

score 5 · Accepted Answer · answered May 11 '17 at 05:15

5

For 010 is decimal 8, so it get 202.

console.log(25.25 * 010);

answered May 11 '17 at 05:15

LF00

score 0 · Answer 2 · edited May 23 '17 at 12:17

0

Look at this answer for Java: Why "010" equals 8?. JavaScript has to do the same.

The answer is, that an octal number starts with a leading zero 0.

edited May 23 '17 at 12:17

Community

answered May 11 '17 at 05:18

Guybrush

2 Answers2