Question

175

Function to determine if a string contains characters only from another

rated 0 times [ 177] [ 2] / answers: 1 / hits: 22208 / 11 Years ago, thu, june 27, 2013, 12:00:00

I'm working on a validation function for html input tags. I've the string of the value of the particular input and the string containing the allowed characters.

var allowed = 'abcdefghijklmnopqrstuvwxyz;

var value = element.value;

I'd like to write a function to determine if the value contains character only from the allowed string. I'm looking for a straight-forward and simple solution.
Any ideas?

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kiyam

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4 Years ago

answered 11 Years ago estefanib · Accepted Answer

Yes you can use regex

function alphanumeric(inputtxt)  

{   

    var letters = /^[a-z]+$/;  

    //if you want upper and numbers too 

    //letters = /^[A-Za-z0-9]+$/;

    //if you only want some letters

    // letters = /^[azertyuiop]+$/;

    if(inputtxt.value.match(letters))  

    {  

        alert('Your registration number have accepted : you can try another');  

        document.form1.text1.focus();  

        return true;  

    }  

    else  

    {  

        alert('Please input alphanumeric characters only');  

        return false;  

    }  

}