javascript的一个关于循环执行的问题
- HTML code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title></title><script type="text/javascript"> var secs = 5; function Load(){ for(var i=secs;i>=0;i--) { //if(parseInt(i)==0){ //i=5; //}else{ window.setTimeout('doUpdate('+i+')', (secs-i) * 1000); // } } } function doUpdate(num){ document.getElementById('showDiv').innerHTML = '<h2>'+num+'...</h3>'; }</script></head> <body> <script> window.setTimeout("Load()",1000); </script> <div id="showDiv"></div></body></html>我想知道为什么把注释的部分加上代码就有问题了，我是想在页面不断的显示5 4 3 2 1 0 5 4 3 2 1 0 5 4 3.....有大侠
[解决办法]
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<script type="text/javascript">
var i=5;
function Load(){
doUpdate(5);
}
function doUpdate(num){
document.getElementById('showDiv').innerHTML = '<h2>'+num+'...</h3>';
window.setTimeout(function(){doUpdate(i)},(5-i)*1000);
i=i-1;
if(i==0){
i=5;
}
}
</script>
</head>
<body>
<script>
window.setTimeout("Load()",1000);
</script>
<div id="showDiv"></div>
</body>
</html>
这样试试
[解决办法]
- JScript code
<script type="text/javascript"> var secs = 5; function Load(){ for(var i=secs;i>=-1;i--) { //if(parseInt(i)==0){ //i=5; //}else{ window.setTimeout('doUpdate('+i+')', (secs-i) * 1000); // } } } function doUpdate(num){ document.getElementById('showDiv').innerHTML = '<h2>'+num+'...</h3>'; if(num<0){ Load(); } }</script>
[解决办法]
用递归
[解决办法]
你再仔细看下你注释的那串代码，for的条件永远为真，死循环了。。
如果只是不断的输出倒计时。下面的就够用了
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<body>
<div id="showDiv"></div>
<script>
var secs = 5;
function Load(){
if(secs == 0){
secs = 5;
}else{
secs--;
}
doUpdate(secs);
setTimeout(arguments.callee, 1000);
}
function doUpdate(num){
document.getElementById('showDiv').innerHTML = '<h2>'+num+'...</h3>';
}
setTimeout(Load, 1000);
</script>
</body>
</html>