The closure of the first knowledge in JS

Original link: http://www.cnblogs.com/pssp/p/5189345.html

Let me say a closed-bag usage scenario.

No closure versions are used

Window.onload = function () {    var ul = document.getElementsByTagName ("ul") [0];    var li = ul.getelementsbytagname ("li");    for (Var i=0;i<li.length;i++) {        Li[i].onclick = function () {            console.log (i);//No matter how I point it back 6        }    }}

The version of the closure is used

Window.onload = function () {    var ul = document.getElementsByTagName ("ul") [0];    var li = ul.getelementsbytagname ("li");    for (Var i=0;i<li.length;i++) {        (function (i) {            Li[i].onclick = function () {                console.log (i);// Click on first to return to the first few            }}        ) (i)    }}

Comment Area:

for (Var i=0;i<li.length;i++) {
(function (i) {
Li[i].onclick = function () {
Console.log (i); Click on the first few to return to the first few
}
}) (i)
}
is not similar
for (Var i=0;i<li.length;i++) {
function aaa (i) {
Li[i].onclick = function () {
Console.log (i); Click on the first few to return to the first few
}
}
AAA (i);
}
Let the parameters in AAA (i) Get the I value and pass it in.

Related article: About binding an event in a for loop the print variable i is the last time.

The closure of the first knowledge in JS