Tip: Prevent non-integer input

Monday, March 31, 2008 at 9:15 AM

Posted by Vishnu S., Gadget Developer

Certain gadgets, such as calculators or leap year finders, should restrict user input to integer values. To detect when the user starts entering non-integer data into an element such as an edit area, you can use an onkeypress handler:

function onKeyPress() {
  var a = editbox.value;

  if (a*1 == a) {
    // continue the action
  } else {
    // show an error message
  }
}

Have a tip you'd like to share? Send it to gd-developer AT google DOT com. To see all tips, choose the Tips label.