Check if number exists in a number

Question

I have an odd situation, I think...

I am writing some jquery/javascript code to validate numbers and I need to check if a given int exists within the entered number.

So for instance if the number I am checking against is 15 and the persons types in a 1, I need to check and see if that 1 exists within the 15, if it does then return true else return false.

I tried .stringOf but that of course only works on strings.

Any thoughts? Sorry if it is a super simple answer. Thanks in advance.

So far:

var Quantity = parseFloat(entered_value); // 1
var max = 15;
if(max.indexOf(Quantity) >= 0){
    qty = Quantity;
}else{
    qty = max;
}

try converting it to a string to do the check. You can do that easily like this: var maxStr = "" + max, then check maxStr with indexOf — Reason, Jun 03 '13 at 15:14
I would suggest that if you're trying to check for a float value as a substring within a string representation of an integer, then there's a possibility you're going about solving something in a less than ideal way. What is the actual problem you're trying to solve, in context? — Pudge601, Jun 03 '13 at 15:25

score 3 · Accepted Answer · answered Jun 03 '13 at 15:22

3

var Quantity = parseFloat(entered_value); // 1
var max = 15;
if(max.toString().indexOf(Quantity.toString()) >= 0){
    qty = Quantity;
}else{
    qty = max;
}

answered Jun 03 '13 at 15:22

Arun

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score 1 · Answer 2 · edited May 23 '17 at 12:18

1

Just to type out Reason's suggestion

var num = 1,
    max = 15,
    isSubString = (max+'').indexOf(num) > -1;

if ( isSubString ) {
  // Num is a sub string of max
}

edited May 23 '17 at 12:18

Community

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1

answered Jun 03 '13 at 15:17

Andreas Louv

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he is trying to test with a float. What if `num = 1.0` or `num = 1.2` ? – mercsen Jun 03 '13 at 15:19
Then it most likely wouldn't be a substring of max. Unless max is also a float then there would be a change. – Andreas Louv Jun 03 '13 at 15:20
but eve if max is a float like `max = 15.0;` num wouldn't be a substring if `num = 1.0`. i think the problem is not that easy ;) – mercsen Jun 03 '13 at 15:22
@mercsen `parseFloat('1.0') === 1` – Andreas Louv Jun 03 '13 at 15:23
why parsing a float as a float? `parseFloat('1.2') === 1.2` ! there must be a reason for using floats instead of int – mercsen Jun 03 '13 at 15:25
A quick read can be found here: http://stackoverflow.com/questions/9528433/behavior-difference-between-parseint-and-parsefloat – Andreas Louv Jun 03 '13 at 15:27
haha i know this stuff, it was meant to your post befor the edit ;) – mercsen Jun 03 '13 at 15:28
i guess without knowing the reason he wants to check this its not possible to give the correct answer...... – mercsen Jun 03 '13 at 15:29

Check if number exists in a number

2 Answers2