Difference between revisions of "String Functions and Manipulation in VB6"

Revision as of 10:25, 10 January 2008

String Functions and Manipulation in VB6 including common functions such as Asc, Chr, Mid, Join, LSet, StrConv, StrReverse, Filter, Replace

Asc (function)

Returns an Integer representing the character code corresponding to the first letter in a string.

Syntax

Asc(string)

Chr (function)

Returns a String containing the character associated with the specified character code.

Syntax

Chr(charcode)

InStr (function)

Returns a Variant (Long) specifying the position of the first occurrence of one string within another.

Syntax

InStr([start, ]string1, string2[, compare])

Example

Dim SearchString, SearchChar, MyPos
SearchString ="XXpXXpXXPXXP"   ' String to search in.
SearchChar = "P"   ' Search for "P".

' A textual comparison starting at position 4. Returns 6.
MyPos = Instr(4, SearchString, SearchChar, 1)    

' A binary comparison starting at position 1. Returns 9.
MyPos = Instr(1, SearchString, SearchChar, 0)

' Comparison is binary by default (last argument is omitted).
MyPos = Instr(SearchString, SearchChar)   ' Returns 9.

MyPos = Instr(1, SearchString, "W")   ' Returns 0.

InStrRev (function)

Returns the position of an occurrence of one string within another, from the end of string.

Syntax

InstrRev(stringcheck, stringmatch[, start[, compare]])

Mid (function)

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

Syntax

Mid(string, start[, length])

Replace (function)

Returns a string in which a specified substring has been replaced with another substring a specified number of times.

Syntax

Replace(expression, find, replace[, start[, count[, compare]]])

Example

Debug.print Replace("abababa", "a", "")

Example

public Function StripOut(From as string, What as string) as string
  Dim i as Integer
  StripOut = From
  for i = 1 to len(What)
    StripOut = Replace(StripOut, mid$(What, i, 1), "")
  next i
End Function

StrComp (function)

Returns a Variant (Integer) indicating the result of a string comparison.

Syntax

StrComp(string1, string2[, compare])

Return Values

If                                  StrComp returns
string1 is less than string2        -1
string1 is equal to string2 	     0
string1 is greater than string2     1
string1 or string2 is Null          Null