用vb编程： 1+2+3.....+n 输入任意数计算出结果（用6种方法）,小弟急用，盼回复！！！

1
sum=0
for i = 1 to n
sum = sum+i
next i

2
i = 0
Do While i <= n
Sum = Sum + i
i = i + 1
Loop

3
i = 0
Do Until i > n
Sum = Sum + i
i = i + 1
Loop

4
Sum = (1 + n) * n / 2

5
While i <= n
Sum = Sum + i
i = i + 1
Wend

6
While i > n
Sum = Sum + i
i = i + 1
Wend
6种

(1+n)*n/2

for x=1 to n
y=y+x
next x
?y

只有这些了 毕竟初学者啊