为什么到最后只筛选出了小I？
<!DOCTYPE HTML>
<html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>流程控制语句</title>
<script type="text/javascript">
//第一步把之前的数据写成一个数组的形式,定义变量为 infos
var infos=[["小A","女",21,"大一"],["小B","男",23,"大三"],["小C","男",24,"大四"],["小D","女",21,"大一"],["小E","女",22,"大四"],["小F","男",21,"大一"],["小G","女",22,"大二"],["小H","女",20,"大三"],["小I","女",20,"大一"],["小J","男",20,"大三"]];
//第一次筛选，找出都是大一的信息
var dy= new Array();
for(var i=0;i<infos.length;i++){
var j=0
if(infos[i][3]=="大一"){
dy[j]=infos[i];
j++;
}
}
//第二次筛选，找出都是女生的信息
for(var k=0; k<dy.length;k++){
if(dy[k][1]=="女"){
document.write(dy[k])
}
}
</script>
</head>
<body>
</body>
</html>
上面是代码，得到的结果是
小I,女,20,大一
