Question

VB 输入一串字符，统计各字母出现的次数（大小写字母不区分）。 Private Sub Command1_Click()

输入一串字符，统计各字母出现的次数（大小写字母不区分）。
Private Sub Command1_Click()
Dim c As String, x%, a(1 To 26) As Integer
For i = 1 To Len(Text1.Text)
c = UCase(Mid(Text1.Text, i, 1))
If c >= "A" And c <= "Z" Then
j = Asc(c) - 64
a(j) = a(j) + 1
End If
Next i
For j = 1 To 26
Picture1.Print Chr(j + 64) & "=" & "a(j)";
Next j
End Sub
为什么运行后不输入任何东西和输入字母的效果都是A=a（j）B=a（j）...Z=a（j）

Answer 1

Picture1.Print Chr(j + 64) & "=" & "a(j)";中a(j)是不要加“”的，否则就变成了字符串了，还有在picturebox里打印时最好换行，不要打印在一行上，太长了，所以，建议你把后面冒号也去掉，如下：
Private Sub Command1_Click()
Dim c As String, x%, a(1 To 26) As Integer
For i = 1 To Len(Text1.Text)
c = UCase(Mid(Text1.Text, i, 1))
If c >= "A" And c <= "Z" Then
j = Asc(c) - 64
a(j) = a(j) + 1
End If
Next i
For j = 1 To 26
Picture1.Print Chr(j + 64) & "=" & a(j)
Next j
End Sub

追问

嗯，那一开始为什么不用声明a（j）=0？

追答

因为数组在没有赋值的情况下，系统默认为0，所以不用声明a（j）=0的。

Answer 2

只要吧Picture1.Print Chr(j + 64) & "=" & "a(j)";改为Picture1.Print Chr(j + 64) & "=" & a(j);就行了。
Private Sub Command1_Click()
Dim c As String, x%, a(1 To 26) As Integer
Picture1.Cls
For i = 1 To Len(Text1.Text)
c = UCase(Mid(Text1.Text, i, 1))
If c >= "A" And c <= "Z" Then
j = Asc(c) - 64
a(j) = a(j) + 1
End If
Next i
For j = 1 To 26
If j Mod 6 = 0 Then
Picture1.Print Chr(j + 64) & "=" & a(j)
Picture1.Print
Else
Picture1.Print Chr(j + 64) & "=" & a(j);
Picture1.Print Space(3);
End If
Next j
End Sub