Numeric Validation in Java Script

Java Script code For Numeric Validation.

Introduction 

 

In your HTML page add the control you want to validate but for this sample, I used textbox to demonstrate this code, in my textbox control I used onkeyup event to validate whether recently entered character is numeric or not. so you can call this JavaScript code as your requirement in your project.

 

Test.html

<input type="text" id="txt" name="txt" onkeyup="txtValidate(this.id)"/>

JavaScript Code

function txtValidate(txtid)
{
     var ok = 0;
     var a = document.getElementById(txtid).value;

     for (var i = 0; i <= a.length - 1; i++)
     {
          var j = a.charCodeAt(i);
          for (var k = 48; k <= 57; k++)
          {
               ok = 0;

               if (k == j)
               {
                    ok = 1;
                    break;
               }
          }

     }

     if (ok == 0)
     {
          alert("Only Numeric Values Allowed");
          document.getElementById(txtid).value = "";
          for (var i = 0; i < a.length - 1; i++)
          {
               var j = a.charCodeAt(i);
               for (var k = 48; k <= 57; k++)
               {
                    ok = 0;

                    if (k == j)
                    {
                         document.getElementById(txtid).value += a.charAt(i);
                    }
               }

          }
     }
}

I hope this code helps you. Thank you.