JavaScript - onClick to get the ID of the clicked

Question

How do find the id of the button which is being clicked?

<button id="1" onClick="reply_click()"></button>
<button id="2" onClick="reply_click()"></button>
<button id="3" onClick="reply_click()"></button>

function reply_click()
{
}

Answer 1

<button id="1" onClick="reply_click(this)"></button>
<button id="2" onClick="reply_click(this)"></button>
<button id="3" onClick="reply_click(this)"></button>

function reply_click(obj)
{
var id = obj.id;
}

Answer 2

With pure javascript you can do the following:

var buttons = document.getElementsByTagName("button");
var buttonsCount = buttons.length;
for (var i = 0; i < buttonsCount; i += 1) {
    buttons[i].onclick = function(e) {
        alert(this.id);
    };
}​

check it On JsFiddle