Javascript .indexOf not working on an int array

Question

Code:

function showlayer(name){
    var size = js_array.length
    var index = js_array.indexOf(name);
    var plusOne = js_array[index+1];
    document.write("" + name + "<br />" + js_array + "<br />" + index + "<br />" +
                   plusOne + "<br />" )
    ...
}

Output:

301
300,299,301,290,303,304,302,310,291,306,308,305,307,292,294,295,309
-1
300

All possible values of name are in the array, but for some reason indexOf() never finds them. Whats up?

Appleton

Are you comparing numbers to strings? – Stadium

This isn't the problem you are specifically seeing here, but it is worth pointing out that Array.indexOf() isn't available on IE8 and lower. See here: #2790501. – Irrevocable

@Irrevocable Yeah I know. Hope it won't be too much of an issue – Appleton

That stackoverflow link has a polyfill to add support for Array.indexOf() to IE6-8 if you need it. I prefer to only support IE9 and up now-a-days, but there are still a lot of IE8 people out there. – Irrevocable

Answer 1

Try this instead:

...
var index = js_array.indexOf(parseInt(name, 10)); // so that it does not try to compare strings...
...

Stoup

@Appleton happy to help ^_^ – Stoup

@gta0004: Apparently, name is not an int. – Stadium

@Stadium hehe that is most probably true. – Stoup

@Stadium look at the output. 301 = name. so idk – Appleton

@Appleton output typeof name and your shall see ^_^ – Stoup

Or, simply cast the key to Int: array.indexOf(+name). – Builder