ASC and AscB, AscW
The ASC function returns the ANSI character code corresponding to the first letter of the string.
ASC (String)
The AscB function is used in conjunction with a string containing byte data. Instead of returning the character code for the first character, AscB returns the first byte.
The ASCW is provided for 32-bit platforms that use Unicode characters. It returns the Unicode (wide) character code, so you can avoid code conversions from ANSI to Unicode.
Chr and ChrB, ChrW
The CHR function returns the character corresponding to the specified ANSI character code.
CHR (CharCode)
The ChrB function is used in conjunction with the byte data contained in the string. ChrB is not a character that returns one or two bytes, but a character that always returns a single byte.
The CHRW is provided for 32-bit platforms that use Unicode characters. Its argument is a Unicode (wide-character) character code, so you can avoid converting ANSI to Unicode characters.
Left and LeftB
The left function returns the specified number of characters from the left-hand side of the string.
Left (string, length)
The LeftB function is used in conjunction with byte data contained in a string. Length is not the number of strings returned, but the number of bytes.
Len and LenB
The Len function returns the number of characters within a string, or the number of bytes required to store a variable.
Len (String | varname)
The LenB function is used in conjunction with the byte data contained in the string. Instead of returning the number of characters in the string, LenB returns the number of bytes used to represent the string.
Mid and MidB
The Mid function returns a specified number of characters from a string.
Mid (String, start[, length])
The MidB function is used in conjunction with the byte data contained in the string. The parameter is not the specified number of characters, but the number of bytes.
Right and RIGHTB
The right function returns a specified number of characters from the right-hand side of the string.
Right (string, length)
The RIGHTB function is used for byte data in a string, and the length parameter specifies the number of bytes to return, not the number of characters.