2012年计算机等级考试二级VB考点及习题(4)
# ?' b, d. Y, y5 y4 B) D' q例如:1、if 语句:
) `- Q4 ~! i! B3 k. m0 Y Private Sub Form_Click()5 ]* v, r" ?( I7 ^/ ?$ @
Dim x As Integer, y As Integer
& i; q, F& I: @ Dim z As Single6 W$ k; @9 X' E$ S1 i3 I( t
x = 0.2
, Y) ]6 T& n' ? y = 1
9 K, ^6 e+ b/ N2 T) I7 m If (x >= 1) Then
+ F7 C& e8 O( d( R6 S8 Q z = Log(x)
5 V7 s; V/ h0 G' v( n ElseIf x >= 0 And x < 1 And y >= 0 Then1 w1 D1 I% s% _. W( c$ ]
z = 2 * x - y
9 @; d: f0 ]2 f1 P$ I/ j: h1 D Else
: f/ t( c$ q) I z = Exp(x + y)
; m) U) `& U7 J; H9 B1 n& F- [ End If
. k3 ? P& K# K& L/ N Print "z=" + Str(z)+ F0 M- F: A6 \8 e5 x, [' ]# m
End Sub
! v. h+ D1 X, w* {- o W; `0 i 结果: z=-1
. b. g# r* P# Q5 V: O 2、Select Case语句" F/ ?- k" j) W4 Z4 Y
Private Sub Form_Click()
: Z4 O/ N+ t# ?* E& Q. r/ { Dim ch As String, i As Integer. K0 h7 r+ s5 G1 B; k
ch = "c"4 q7 Q* ^" m5 ` M, m8 T* Y5 o( ?
Select Case ch2 L: L3 v* f7 N3 w0 T4 z( [. l; ^
Case "A", "a"8 U# Y, X: a2 I* N( G, ~3 K7 a: D
i = 1) D A- i+ E% I/ p q
Case "B", "b"
5 O( t8 C2 ~ z# n7 T i = 2/ ]0 _4 D0 J1 N: u: S+ ?: Z: Y
Case "C", "c"
6 P3 a0 }5 r- y2 S4 Y! ?, E' U8 [4 ]8 B i = 3
o$ z6 r0 e1 k Case "D", "d"* [4 w+ @9 z! o
i = 4
4 A! i/ j5 E9 E( m Case Else
8 `+ R6 L' q/ z4 i& r0 k: J i = 5
5 d o. B1 J7 H4 h9 c& N End Select7 R2 x) w# i* D' v
Print "运行结果" + Ucase(ch) + Str(i)) m' E5 R/ h6 I+ Y2 h
End Sub1 e. V7 D. A- g! r, H; v
结果:运行结果C3 E4 a+ }7 x) Q* w5 W' F
② 循环结构. ^8 C/ r# U4 r" q
1、For------Next (循环次数的计算)
# `0 ^% l) J7 f- u) O& t 特例:2 N/ d% F: X0 {; Y# A6 R/ N$ W9 Y
) u1 P* t+ s5 U
例如:有循环:for I=n1 to n2 step n3 下列哪些语句会影响循环次数( )
, V) C9 m9 y6 t A. n1=n1+I
. }& u6 n+ h& {' @( m B. n3=2*n3( m: U5 |& ?% N7 l; G
C. n2=n2+n3
" {0 o+ O& F3 V2 A% p" k* ~, i. ^ D. I=I+n3
! Q; N+ H5 g! G- M 2、Do------Loop (While,Until)" O$ j% q p9 V3 u, C* r% w
例如:运行下面的程序,单击窗体后在窗体上的内容是( );若将程序中的A语句与B语句的位置互换,再次执行程序,单击窗体后在窗体上显示的内容是( ), M% ~2 y) N4 b! l6 w
Private Sub Form_Click()
* v' V% K- b% F Dim a As Integer, b As Integer
" x$ @: z+ d- _# Y1 L5 B1 A a = 0: b = 0
! M" T, ~: J, k0 _, C% U Do While a = 10 Then Exit For, v8 G' @$ V1 |- ~. h# y( N4 o
Next i
/ ?8 ?& k" I+ c: {; O Print i, p, n; i5 C# K5 a m! b
End Sub5 E' V0 Z- L; K8 V6 y; S' X$ p
一、 InputBox函数
& P9 G1 g* V1 R, m5 W MsgBox函数 (注意参数含义及顺序)
, ]7 c ^# _0 f x=InputBox(_____,______,_______): o5 z: y* h: l3 W7 d5 L$ g. X3 u ^
写出显示下图信息框的MsgBox函数 |