Question

I have this unordered list which contains some inputs, what I want to do is to type a value on the first input, like “1”, then all the other inputs, in order, gets 2, 3, 4, 5

Answer 1

You could do something like this, parse the first value then increment the rest based on their index:

$("ol input:first").keyup(function() {
  var val = parseInt(this.value, 10);
  $("ol input:gt(0)").val(isNaN(val) ? '' : function(i) { return val + i + 1; });
});​

You can give it a try here. The if/else conditional is checking if the value’s legit, e.g. if you hit backspace and it’s empty you won’t get NaN in every following input, inside we’ll blank out the value so it’s handled gracefully.