<script>
var sum = 0;
for(var i = 1 ; i <= 100; i++){
sum += i;
}
document.writeln("1~100的累加和为:", sum);
</script>
<script>
var sum = 0;
for(var i = 1 ; i <= 100; i++){
sum += i;
}
document.writeln("1~100的累加和为:", sum);
</script>