I want to check if the value entered by the user is a valid integer using jquery

I have tried this code but it always seems to return true:

if ((manageridEntered === "") || ($.isNumeric(manageridEntered))) {
  success = false;
}

I want to check if the value entered by the user is a valid integer using jquery

I have tried this code but it always seems to return true:

if ((manageridEntered === "") || ($.isNumeric(manageridEntered))) {
  success = false;
}

• javascript
• jquery

• 5 Have you seen the documentation at api.jquery./jQuery.isNumeric? It states: "[...] $.isNumeric() returns true only if the argument is of type number, or if it's of type string and it can be coerced into finite numbers. In all other cases, it returns false." – gus27 Commented Nov 15, 2016 at 12:44
• @gus27 Can you try with number followed by alphabets? Eg:- 2ab show IsNumeric true, this is wrong na? – Coding world Commented Aug 21, 2019 at 9:05

9 Answers 9

You could use classic JavaScript :

var isNumber = Number.isInteger(yournumber);

Or if you want to check if it isn't (without using !) :

var isNaN = Number.isNaN(yournumber);

console.log(Number.isInteger(0.1));       // false
console.log(Number.isInteger(1));         // true
console.log(Number.isInteger(-100000));   // true
console.log(Number.isInteger(Math.PI));   // false
console.log(Number.isInteger(-Infinity)); // false
console.log(Number.isInteger(true));      // false
console.log(Number.isInteger(NaN));       // false
console.log(Number.isInteger(0));         // true
console.log(Number.isInteger("10"));      // false

No need to use jquery

You can use javascript isNaN()

isNaN() accepts decimal numbers also

return !isNaN(manageridEntered))

or

You can use plain javascript regex here to match only digits

return new RegExp('^\\d+$').test(manageridEntered))

You can use vanilla JavaScript:

success = !manageridEntered.length || parseInt(manageridEntered) == manageridEntered;

Use regex

var intRegex = /^\d+$/;
var floatRegex = /^((\d+(\.\d *)?)|((\d*\.)?\d+))$/;

var str = $('#myTextBox').val();
if(intRegex.test(str) || floatRegex.test(str)) {
   alert('I am a number');

}

Example taken from checking if number entered is a digit in jquery

$('.submitBtn').click(function() {
  var Number = $('#Number').val();
if ((Number === "") || ($.isNumeric(Number))) {
  alert('Valid NUmber');
}else{
  alert('Not Valid NUmber');
}
});

<script src="https://ajax.googleapis./ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<form method="post" action="">
   Inateger Value: <input type="text" name="Number" id="Number" />
  <input type="submit" value="Submit" class="submitBtn">
</form>

isNumeric is checking for a number (which could be wrapped in a string too), not an integer. Beside that isNumeric() is not always returning true like you can see in the following snippet using JQuery 2.1.1.

console.log($.isNumeric('a'));    // false
console.log($.isNumeric('1'));    // true
console.log($.isNumeric(1));      // true
console.log($.isNumeric(1.5));    // true
console.log($.isNumeric('1.5'));  // true

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Please try this:

if(Math.floor(manageridEntered) == manageridEntered && $.isNumeric(manageridEntered)){
     //code here
}

Using Regex you can achieve it see below code

$(document).ready(function () {
            $("#button").on("click", function () {

                var patt = new RegExp("^[0-9]*$");
                if (patt.test($("#number").val())) {
                    alert("true")
                } else {
                    alert("false")
                }
            });

        });

<script src="https://ajax.googleapis./ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<input type="text" id="number" />
<input type="button" id="button"  value="Check"/>

returns true if it's an integer

if(manageridEntered == parseInt(manageridEntered))