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JavaScript solves loop-bound events with closures

Source: Internet
Author: User
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Example:

<!DOCTYPE HTML><HTML><Head>    <MetaCharSet= "Utf-8"></Head><Body>    <Button></Button>    <Button></Button>    <Button></Button></Body><Scripttype= "Text/javascript">window.onload=function(){    varBtns=document.getElementsByTagName ("Button");  for(varI=0; I<Btns.length;i++) {Btns[i].onclick=function() {alert (i)}; }}</Script></HTML>

The result of the execution is that each button click after the popup is 3;

Therefore, we use the characteristics of closures to solve cyclic binding, I variable assignment problem, modify the script part of the code as follows:

<script type= "Text/javascript" >window.onload=function(){    varBtns=document.getelementsbytagname ("button");  for(vari=0;i<btns.length;i++){        varCol =NewAlertfunc (i); Btns[i].onclick=Col.clickfunc; //btns[i].onclick=function () {alert (i)};    }}functionAlertfunc (i) { This. clickfunc=function() {alert (i)}; }</script>

success~

JavaScript solves loop-bound events with closures

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