Get id attribute of all elements with a certain class.

gistfile1.js

//Without jQuery

var elements = document.getElementsByClassName('clicked'),		//Be careful: won't work in IE 6,7,8
	ids = [];

for(var i = 0; i < elements.length; i++){
	ids.push(elements[i].id);
}

console.log(ids);

//==============================================================

//With jQuery

var ids = [];
$.each($('.clicked'), function(){
	ids.push($(this).attr('id'));
});

console.log(ids);