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标题: Mid函数的用法? [打印本页]

作者: china-girl    时间: 2002-11-26 04:53
标题: Mid函数的用法?
谢谢!
作者: cattjiu    时间: 2002-11-26 16:10
完全安装OFFICE,看帮助。
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Mid Function
      

Returns a Variant (String) containing a specified number of characters from a string.

Syntax

Mid(string, start[, length])

The Mid function syntax has these named arguments:

Part Description
string Required. String expression from which characters are returned. If string contains Null, Null is returned.
start Required; Long. Character position in string at which the part to be taken begins. If start is greater than the number of characters in string, Mid returns a zero-length string ("").
length Optional; Variant (Long). Number of characters to return. If omitted or if there are fewer than length characters in the text (including the character at start), all characters from the start position to the end of the string are returned.



Remarks

To determine the number of characters in string, use the Len function.

Note   Use the MidB function with byte data contained in a string, as in double-byte character set languages. Instead of specifying the number of characters, the arguments specify numbers of bytes. For sample code that uses MidB, see the second example in the example topic.
Mid Function Example
The first example uses the Mid function to return a specified number of characters from a string.

Dim MyString, FirstWord, LastWord, MidWords
MyString = "Mid Function Demo"    ' Create text string.
FirstWord = Mid(MyString, 1, 3)    ' Returns "Mid".
LastWord = Mid(MyString, 14, 4)    ' Returns "Demo".
MidWords = Mid(MyString, 5)    ' Returns "Function Demo".

The second example use MidB and a user-defined function (MidMbcs) to also return characters from string. The difference here is that the input string is ANSI and the length is in bytes.

Function MidMbcs(ByVal str as String, start, length)
    MidMbcs = StrConv(MidB(StrConv(str, vbFromUnicode), start, length), vbUnicode)
End Function

Dim MyString
MyString = "AbCdEfG"
' Where "A", "C", "E", and "G" are DBCS and "b", "d",
' and "f" are SBCS.
MyNewString = Mid(MyString, 3, 4)
' Returns ""CdEf"
MyNewString = MidB(MyString, 3, 4)
' Returns ""bC"
MyNewString = MidMbcs(MyString, 3, 4)
' Returns "bCd"


作者: zhengjialon    时间: 2002-11-26 16:12
这些帮助里都有十分详细的论述:如果没有帮助,到这里下一个:
http://www.office-cn.net/bbs/dispbbs.asp?boardID=2&RootID=11727&ID=11727
作者: 大熊    时间: 2002-11-26 17:56
这谁啊,用的是英文版的帮助!
作者: cattjiu    时间: 2002-11-26 19:23
还别说,英文版兼容性更好呢:)




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