javascript onclick increment number

Question

With javascript, how can I do it so when i click a form button it adds 1 to a number? The number it increments could be in a form text field or something.

Obviously it'd be on onclick but I'm not sure of the code.

Answer 1

In its most basic incarnation..

JavaScript:

<script>
    var i = 0;
    function buttonClick() {
        document.getElementById('inc').value = ++i;
    }
</script>

Markup:

<button onclick="buttonClick()">Click Me</button>
<input type="text" id="inc" value="0"></input>

• DEMO