jQuery each, for and closure

gistfile1.txt

// OMG I heard jQuery.fn.each was like a HUGE perf hit!
// So I'm going to use a native for loop instead!
var lis = $("li"),
    l = lis.length, // 5
    li;
for (var i=0;i<l;i++) {
    li = lis.eq(i);
    li.click(function() {
       alert("You clicked the "+ i +"th item");
       // No matter which item is clicked, it always alerts 5!
    });
}

var lis = $("li"), l = lis.length, i = 0, li;
for (i=0;i<l;i++) {
    (function(i) {
        // i is now local to this IIFE (immediately-invoked function expression)
        li = lis.eq(i);
        li.click(function() {
           alert("You clicked the "+ i +"th item");
        });
    })(i);
}
 
// Just use jQuery's .each, it's not actually a serious performance concern
lis.each(function(i,elem) {
   $(this).click(function(event) {
    alert("jQuery's each says you clicked the "+ i +"th item");
  });
});