How to check if a string is an int?

Question

I have a small if where I'd just like to check a string to see if it is an integer. I am using JQuery to do this.

JQUERY:

 var intRegex = /[0-9 -()+]+$/;


 if ($('#txtGRCSelect').val() != '' && intRegex($('#txtGRCSelect').val())) {
                        alert("No CASE");
                        $("#ErrorBoxText").html("Error : A Role has not been selected.");
                        rt = true;
                    }

It doesn't work, can anybody help me and tell me why?

@ArunPJohny Sorry, realised I forgot to add it in, it's now added — Andrew Kilburn, Jul 20 '15 at 10:36
Surely a regular expression test for an integer should be something more like `/^[-+]?\d+$/`? Your current test would validate `asdjhiujb2-(+)`. — Phylogenesis, Jul 20 '15 at 10:40
@Phylogenesis I have changed the regex according to suggestions, still not getting any results — Andrew Kilburn, Jul 20 '15 at 10:42
`if (! /^[-+]?\d+$/.test($('#txtGRCSelect').val())) { /* Not a valid integer */ }`. See [this fiddle](http://jsfiddle.net/nnh1njg8/). — Phylogenesis, Jul 20 '15 at 10:44
use jQuery.isNumeric(): http://stackoverflow.com/questions/14464213/jquery-check-if-value-is-numeric — Yuyutsu, Jul 20 '15 at 10:52

Arun P Johny · Accepted Answer · 2015-07-20T10:41:50.437

2

intRegex is a regex object so call the test method which will return true is the string satisfies the regex

$('button').click(function() {
  var intRegex = /^[0-9 -()+]+$/; //may have to add `^` at the beginning to check the string is completely matches the regex, else it will just test whether the string ends with the given characters
  if ($('#txtGRCSelect').val() == '' || !intRegex.test($('#txtGRCSelect').val())) {
    alert("No CASE");
    $("#ErrorBoxText").html("Error : A Role has not been selected.");
    rt = true;
  }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<input id="txtGRCSelect" />
<button>Test</button>

edited Jul 20 '15 at 10:41

answered Jul 20 '15 at 10:36

Arun P Johny

384,651
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Hi, I presumed you meant the 'test' method? This did not work either as it hasn't reached my alert. – Andrew Kilburn Jul 20 '15 at 10:38
@ArunPJohny `intRegex.text(` should be `test(` – Tushar Jul 20 '15 at 10:40

score 0 · Answer 2 · answered Jul 20 '15 at 10:42

0

var ex=/^[0-9]*$/;
var A=$('#txtGRCSelect').val();
if(ex.test(A)==true)
{
alert("Value integer.");
}

answered Jul 20 '15 at 10:42

Suman Banerjee

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4
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score 0 · Answer 3 · answered May 30 '16 at 18:55

0

Method 1

function IsNumeric(x){    
var patt = new RegExp("^[0-9]+$");    
return patt.test(x);
}

Method 2

function IsNumeric(x){
x=x.replace('.','#');
return!isNaN(parseFloat(x))&&isFinite(x);
}

example:

IsNumeric(1)

answered May 30 '16 at 18:55

Sarath Ak

7,903
2
47
48

How to check if a string is an int?

3 Answers3