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A random roll call function implemented in javascript_Basic knowledge

WBOY
WBOYOriginal
2016-05-16 16:38:411805browse

This is actually a way to practice JS random numbers. First, pre-write everyone’s name in an array, and then let the values ​​​​in the array be quickly displayed in the area. When you press stop, the scroll will will stop achieving random effects. 

<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8" />
	<title>JS写的随机点名 - 琼台博客</title>
	<script type="text/javascript">
	var isRun=true;
	var a = ["张三","李四","王五","赵六"];	
	var a2 = new Array();
	function action(str){
		var s = document.getElementById("bt").value;
		if(s=="开始"){
			isRun=true;
			run();
			document.getElementById("bt").value="结束";
		}else{
			isRun=false;
			document.getElementById("bt").value="开始";
		}
	}
	function run(){
		var i = Math.floor(Math.random() * a.length+ 1)-1;
		document.getElementById("show").innerHTML=a[i];
		if(isRun==false){
			var b =true;
			for(var j in a2){
				if(a2[j]==i){
					b=false;
				}
			}
			if(b){
			 	a2[a2.length]=i;
				return;
			}
		}
		setTimeout("run()",10);
	}
</script>

</head>

<body>
	<div style="text-align:center; margin-top:100px;width:100%;">
		<div id="show" style="margin:auto;font-size:50px;width:100px;height:50px; background:#FFEEFF"></div>
		<div style="margin-top:20px;">
			<input id="bt" type="button" onclick="action()" value="开始"/>
		</div>
	</div>
</body>
</html>

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