双重循环

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>双重循环作业</title>
</head>
<body style="text-align:center;">
<script>
document.write("<h2>矩形</h2>");
document.write("<table>");
for(i=1;i<=10;i++){
document.write("<tr></br>");
for(x=1;x<=10;x++){
document.write("<tb>"+"*"+"</tb>")
}
document.write("</tr>");
}
document.write("</table>");
//作业二
document.write("<h2>等腰三角形</h2>");
document.write("<table>");
for(deng=1;deng<=10;deng=deng+2){
document.write("<tr></br>");
for(ya=1;ya<=deng;ya++){
document.write("<tb>" + "*" + "</tb>")
}
document.write("</tr>");
}
document.write("</table>");
//作业三
document.write("<h2>学生成绩</h2>");
var cv=prompt("请输入总共有多少名同学的成绩","");
var we=0;
for(cheng=1;cheng<=cv;cheng++){
var ji=prompt("请输入第"+cheng+"位同学的成绩","");
if(ji>=80) {
we++
}
}
document.write("80分以上学生有:" +we+"位");
//作业四
document.write("<h2>菱形</h2>");
for(nb=1;nb<=7;nb=nb+2){
for(mn=1;mn<=nb;mn++) {
if(mn==1||mn==nb){
document.write("*")
}else {
document.write("&nbsp")
}
}
document.write("<br/>")
}
for(y=1;y<=7;y=y+2){
for(z=7;z>=y;z--) {
if(z==y||z==7){
document.write("*")
}else {
document.write("&nbsp")
}
}
document.write("<br/>")
}

</script>
</body>
</html>
posted @ 2018-05-09 07:14  dongdongyang  阅读(215)  评论(0)    收藏  举报