Javascript String indexOf not working as expected

Question

I must be missing something .. not sure why my JavaScript is failing or not working

var discount = 10;
var newTemp;

if (discount != null) {
    if (discount.indexOf("%") > -1) {
        newTemp = discount.substring(0, 2) + '%';
    } else {
        newTemp = discount;
    }
 } //end of outer if

Above script works when discount = "10.0%" But fails when discount = 10

maynot be best way, but all I am trying to do is if discount value contains % sign then setting newTemp variable with new value. Else just keep it as is.

Any idea, why control fails when discount value is = 10

I do not see any error. I did quick debug by placing alert and it stops at if (discount.indexOf("%") > -1) if the value of discount=10 — Jagdish
– Jagdish, Commented Apr 15, 2014 at 2:06

Hugo Silva · Accepted Answer · 2014-04-15 01:45:00Z

4

because "10%" is a string, therefore it has a indexOf method, and 10 is probably an integer or number.

Try discount.toString().indexOf('%')

answered Apr 15, 2014 at 1:45

Hugo Silva

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3 Comments

Jagdish Over a year ago

I think you are right, it is treating 10 as number, however i tried your .toString() solution but did not work

Hugo Silva Over a year ago

it is too hard to help you with the information you provide. You should consider improving your debugging process - getfirebug.com/javascript

Jagdish Over a year ago

thank you for your feedback, i changed a logic little bit but understood overall issue was because of variable value is treated as number.

Walter Stabosz · Accepted Answer · 2014-04-15 01:54:42Z

0

It's because you're not appending the '%' in the else branch.

var newTemp;
if (discount != null) {
    if (discount.indexOf("%") > -1) {
        newTemp = discount.substring(0, 2);
    } else {
        newTemp = discount;
    }
 } //end of outer if
 newTemp += '%';

also as Hugo said, the number 10 does not have the indexOf method, which is a string method.

edited Apr 15, 2014 at 1:54

answered Apr 15, 2014 at 1:48

Walter Stabosz

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1 Comment

nodws Over a year ago

.toString() was the key for me!

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