javascript returns 9 for 0011 [duplicate]

问题

This question already has answers here:

How do I work around JavaScript's parseInt octal behavior? (10 answers)

Closed 4 years ago.

I have a function where I passes the value dynamically

<a href="javascript:void(0);" onclick="searchError(0011)">0011</a>

In javascript am just passing this value and it returns me 9

JS

function searchError(s){
        alert(s);           
}

Need help to understand why ?

I fixed it by quoting the value like

<a href="javascript:void(0);" onclick="searchError('0011')">0011</a>

JS Fiddle

回答1:

0011 is an octal number since it has a leftmost 0 so its equal to 0 x 8² + 1 x 8¹ + 1 x 8⁰ = 9. Originally the value was interpreted as a numeric. Enclosing it in quotes caused it to be treated as a String literal.

来源：https://stackoverflow.com/questions/27871143/javascript-returns-9-for-0011