Question

VB 中求100 到200之间的素数

这是我写的代码，不知哪有错，就是输不出来。
Private Sub Command1_Click()
Dim a, b As Integer
For a = 100 To 200
For b = 2 To a - 1
If a Mod b = 0 Then
Exit For
end if
Next b
Next a

For a = 100 To 200
If b >= a Then
Print a
End If
Next a
End Sub
别复制我的啊``

Answer 1

你的程序只是判断到素数就跳出循环，就然无法求100 到200之间的素数。应该加上打印语句。

For i = 101 To 200
For j = 2 To i - 1
If i Mod j = 0 Then
Exit For
End If
Next j
If j = i Then Print i;
Next i

另外，你的素数判断标准并不见得高明，如果要求到10000之间的话，就要较长的时间了。

Answer 2

Private Sub Command1_Click()
Dim a As Integer
Dim b As Integer

For a = 100 To 200
For b = 2 To a - 1
If a Mod b = 0 Then
Exit For
end if
Next
Next

For a = 100 To 200
If b >= a Then
Print a
End If
Next
End Sub
定义的问题

Answer 3

Dim sum %,i%,j%,flag%
for i=100 to200
flag = 1
For j=2 to i-1
IF i mod j =0 then
Flag=0
Exit for
End if
Next j
if flag =1 then
Sum =sum +1
End IF
Next i
Text1.text =sum