There are many useful string functions in Visual Basic 6. The string functions are defined in the “Strings” module, which can be found in the Object Browser.
Left
The Left function extracts characters from the left of the string.
Syntax
Left(string, n)
n is the number of characters to be extracted.
Example
Print Left("Visual", 3)
Output: Vis
Right
The Right function extracts characters from the right of the string.
Syntax
Right(string, n)
string is the character string, n is the number of characters to be extracted.
Example
Print Right("Visual", 3)
Output: ual
Mid
Use the the Mid function to extract characters from the middle of the string.
Syntax
Mid(string, m, n)
string is the character string, the extracted string will begin at mth character, n is the number of characters to be extracted.
Example
Print Mid("Visual", 3, 2)
Output: su
Len
The Len function calculates the number of characters in a string.
Example
Private Sub cmdCount_Click()
Dim str As String
str = "Visual Basic"
Print Len(str)
End Sub
Output: 12
InStr
The InStr function returns the position of first occurrence of a sub-string contained in a string.
Syntax
Instr(str1, str2)
Example
Dim str As String str = "Visual Basic" Print InStr(str, "Basic")
Output: 8
Chr & Asc
The Chr function converts an ASCII value to character and Asc function converts the character to ASCII.
Syntax
Chr(ASCII value)
Asc(chr)
Example
Print Chr(65)
Output: A
Example
Print Asc("A")
Output: 65
Chr(9) and chr(13) are the Tab and Carriage-return characters respectively.
Example
Print "Hello" & Chr(9) & "world"
Output: Hello world
Print "Hello" & Chr(13) & "world"
Output:
Hello
world
Str
The Str function returns the string representation of a number.
Syntax
Str(n)
Example
Print str(5) + str(7)
Output: 57
LCase & UCase
The LCase function converts an upper case string to lower case and the UCase converts a lower case string to upper case.
Example
Private Sub cmdChangeCase_Click()
Dim s As String
s = "HELLO"
Print LCase(s)
End Sub
Output: hello
Example
Dim s As String s = "hello" Print UCase(s)
Output: HELLO
Trim
The Trim function returns a string without leading and trailing spaces.
Example
Dim s As String s = " HELLO" Print Trim(s)
Output:
HELLO
LTrim & RTrim
The Ltrim function trims leading spaces and the RTrim function trims trailing spaces from a string.
StrReverse
The StrReverse function reverses a string.
Example
Print StrReverse("Basic")
Output: cisaB
Space
Space function returns a specific number of spaces.
Example
Print Space(10) + StrReverse("Basic")
Output:
Basic
StrConv
The StrConv function converts the string into a particular case, e.g upper case, lower case and proper case.
Example
Print StrConv("hello", vbUpperCase)
Output: HELLO
Print StrConv("hello", vbProperCase)
Output: Hello
StrComp
The StrComp function compares two strings to check whether they match or not. It returns 0, if the two strings match with one another.
str = StrComp("vb", "vb", vbTextCompare) 'Returns 0
str = StrComp("vb", "VB", vbTextCompare) 'Returns 0
str = StrComp("vb", "VB", vbBinaryCompare) 'Returns 1
If the optional argument is vbTextCompare then this is a case insensitive comparison, if vbBinaryCompare then it’s a case sensitive comparison.
Tab
The Tab(n) function lets the string be displayed at nth position.
Example
Print Tab(20) ; "Language"
Output:
Language
Replace
The Replace function finds a sub-string in a string and replaces the sub-string with another.
Example
newvalue = Replace("months", "s", "1") 'Returns month1