Question

I have an HTML form

<div class="field"> 
  <label for="num1">Number 1</label> 
  <input id="num1" type="text" /> 
</div> 
<div class="field"> 
  <label for="num2">Number 2</label> 
  <input id="num2" type="text" /> 
</div> 

When “Number 1” is changed, I’d like to change “Number 2” to match it. So this JQuery code:

$('#num1').change(function() {
  var one = this.val();
  $('#num2').val(one);
});

but it says:

Uncaught TypeError: Object #<HTMLInputElement> has no method 'val'

on the line

var one = this.val()

What am I doing wrong?

Answer 1

.val() is only defined on jQuery objects. this returns the DOM object, which does not have this property.

To fix your code:

1. Use $(this).val(), or
2. Use this.value