Substring (String function)

From m204wiki
Revision as of 15:28, 22 February 2011 by Dme (talk | contribs)
Jump to navigation Jump to search

Return a substring of the method object string (String class)


The Substring intrinsic function returns a specific number of bytes starting at a specific position in the method object string, possibly padding it on the right.

Syntax

%outString = string:Substring( position, [length], [Pad= c])

Syntax terms

%outString A variable to receive the string result of the Substring method.
string The input method object string
position The byte number in the method object that is the starting point of the substring that is returned. The first character from the left in the method object is byte number 1.
length An optional, numeric value that is the number of bytes to return. If the method object string has fewer characters than the requested bytes (starting at the position), it is either padded to the requested length, or the entire method object string starting at the start position is returned with no padding, depending on the value of the Pad parameter. If you do not specify a length value, Substring returns everything in the method object string from the position character to the end of the string.
Pad This is an optional, but nameRequired, parameter that specified the character used to pad the result string, on the right, if it's shorter than the requested length. char defaults to a null string, which means no padding is done.

Usage notes

  • The length must be a non-negative number. A negative number results in request cancellation.
  • The Pad parameter must be either null or a single character. A longer value results in request cancellation in Sirius Mods version 7.2 and in a compilation error in Sirius Mods version 7.3 and higher.
  • If the starting position is known to be 1, it might be tidier and slightly more efficient to use the Left method instead of Substring. Substring is available as of Sirius Mods version 7.2.

Examples

  1. The following statement places into %y the 5 bytes of %x starting at the third byte. If %x is shorter than 7 bytes, then all of %x is copied into %y:

    %y = %x:substring(3, 5)

  2. The following statement displays 'psi':

    printText {'Ypsilanti':substring(2, 3)}

  3. The following request displays '123456':substring(3) = 3456:

    begin printText {~} = {'123456':substring(3)} end

See also

  • For details of the printtext statement, please see printText.