pass element's data to function's parameter when using onclick event listener?

Question

HTML:
<input class="c" id="1" type="button" onclick="func()"/>

JavaScript:
func(parameter) {
scripts
}

I basically want to pass 1 (id name) to the parameter when the button is clicked. or if the button is the third element in the page which has class name of "c", I want to pass 3 to the function when it's clicked. Is there any way?

Answer 1

HTML
<input class="c" id="1" type="button" onclick="func(this.id)" value="Test 1"/>

JS
function func(id) {
alert(id);
}

Hth, cmiiw