循环语句_百度文库.doc

实验 实验教室 实验名称：循环语句 实验目的： 实验内容及步骤 操作1：单循环练习 Private Sub Command2_Click( S = 0 I = 1 Do While I = 10 S = S + I I = I + 1 Loop Print S End Sub Private Sub Command3_Click( S = 0 I = I Do S = S + I I = I + 1 Loop Until I 10 Print S End Sub Private Sub Command1_Click( S = 0 For I = 1 To 10 S = S + I Next I Print S End Sub 操作2。双循环练习 思考: 1.FOR与DO WHILE循环结果的异同点何在? 2. DO WHILE与 LOOP UNTIL 的不同点何在? 3.什么循环是活循环? 什么循环是死循环? 什么情况下不进入循环? For I = 1 To 4 Print Space(10; For J = 1 To 4 If J = I Then Print 1; Else Print O; End If Next J Print Next I For I = 1 To 5 For J = 1 To I Print *; Next J Print Next I For I = 1 To 5 Print Space(11 - I; For J = 1 To 2 * I - 1 Print *; Next J Print Next I 打印乘法表 For i = 1 To 9 For j = 1 To i Print i * j; Next j Print Next I ----------------------- For i = 1 To 9 For j = 1 To 9 Print i * j; Next j Print Next i Form1.Cls GOTO句的用法 Dim M%, T As Integer T = 1 M = InputBox(请输入一个整数 For i = 2 To M - 1 If Val(M Mod i = 0 Then T = 0 GoTo AAA End If Next i AAA: If T = 1 Then Form1.Print Str(M + 是素数 End If If T = 0 Then Form1.Print Str(M + 不是素数 End If 思考: 1. 判断一个数是否是素数的依据是什么? 2. GOTO AAA在程序的作用? 3. T变量在程序的作用是什么? 4显示句Form1.Print Str(M + 是素数 中STR(函数的用法 EXIT的用法: 语句格式: EXIT FOR , EXIT DO , EXIT FUNCTION 代表语义 产生任意10到20之间整数相加,其和超过500时,停止累加,显示其累加结果 Dim S%, M As Integer S = 0 T = True Do While T M = Int(Rnd( * 11 + 10 S = S + M If S = 500 Then Exit Do End If Loop Form1.Print S 思考: 1. 语句: T = True Do While T 是活循环还是死循环?,如何跳出死循环?