can someone tell me what i am doing wrong here.. i am not getting invalid number alert when i enter 1 1 0r a
function validateNumeric() { var old_val = document.getElementById("tbNumber").value; var new_val = old_val.replace(/^\s+|\s+$/g,""); var validChars = '0123456789.'; for(var i = 0; i < val.length; i++){ if(validChars.indexOf(new_val.charAt(i)) == -1){ alert('Please enter valid number'); return false; } else { document.getElementById("tbNumber").value = new_val; } } return true; } In your for loop test, you're referencing a variable val, which probably comes back as having a length of 0, so your loop will never do anything and the function will simply return true. I'm guessing your for loop should actually look like:
for(var i = 0; i < new_val.length; i++){ ... } There is a much simpler solution: use a regular expression.
Your valid characters are the digits 0 -9, including a decimal point, correct? Well, the RegEx for that is \d. Therefore, this would check if the value entered is numeric:
(/\d/).test( myValue );Therefore, your code just needs to use the RegEx instead of an expensive loop.
function validateNumeric(){ var x = document.getElementById('foo'); var y = x.value.replace(/^\s+|\s+$/g,''); var DIGITS = (/\d/); // Uppercase because this is a constant value if (!DIGITS.test( y )){ alert('Please enter a valid number.'); return false; } else { x.value = y; return true; } }
