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javascriptregex
Mohammadreza Khatami
Mohammadreza Khatami

Reputation: 1332

JavaScript RegEX Test not working

I want to check if input text (amount) is between 1-100 or not but regex test not working.

here is my JS code

<script type="text/javascript" >    

    console.log(document.getElementById("amount").value); // 222

    var regex = /^(100)|[1-9]\d?$/;
    if(regex.test(document.getElementById("amount").value))
    {
        alert('validated')
    }
    else
        alert('error')

</script>

Upvotes: 1

Views: 609

Answers (4)

Bala.. Boppudi
Bala.. Boppudi

Reputation: 1

    <html>
    <head>

    <script>

    function validateValue()
    {
    var amount = document.getElementById('testId').value;
    if((isNaN(amount ))){
    document.getElementById("errorId").style.display= "";
    }
    else
    {
    if(amount>100){
    document.getElementById("errorId").style.display= "";
    }
    else
    {
    document.getElementById("errorId").style.display= "none";
    }
    }
    }

    </script>

    </head>
    <body>

    Enter 1 to 100:<input type="text" onkeyup="validateValue()"         id="testId"/>
    <span id="errorId" style="color:red;display:none"> Not a valid amount</span>
    </body>
    </html>

Upvotes: 0

RomanPerekhrest
RomanPerekhrest

Reputation: 92854

It would be enough to use parseInt() function or Number constructor to perform such a simple validation:

<script type="text/javascript" >
    var amount = Number(document.getElementById("amount").value); // 222
    alert ((amount > 0 && amount <= 100)? 'Valid' : 'Invalid');
</script>

Upvotes: 1

Tushar
Tushar

Reputation: 87203

  1. Wrap the code in DOMContentLoaded event callback
  2. Don't use RegEx. Use comparison operators

Code:

document.addEventListener('DOMContentLoaded', function () {
    // Get the value & convert it into Number
    var value = parseInt(document.getElementById('amount').value, 10);

    // Value between 0 & 100
    if (value > 0 && value <= 100) {
        alert('Valid');
    } else {
        alert('Error');
    }
});

Upvotes: 4

Chris Lear
Chris Lear

Reputation: 6742

If you really want to use regex, this should work:

/^100$|^[1-9]\d?$/

It doesn't allow eg 09, but maybe that's OK.

Upvotes: 0

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