console
function writeDocument(variable){
document.write(variable+"<br/>");
}
writeDocument("for循环------------------------");
var sum=0;
for(var i=1;i<101;i++){
sum+=i;
}
writeDocument(sum);
writeDocument("whlie循环------------------------");
var a=1;
var sum1=0;
while(a!=101){
sum1+=a;
a++;
}
writeDocument(sum1);
writeDocument("do...whlie循环------------------------");
var b=1;
var sum2=0;
do{
sum2+=b;
b++;
}while(b!=101)
writeDocument(sum2);
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<script>
</script>
</head>
<body>
</body>
</html>