Substring (String function)

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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.


%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 string that is the starting point of the substring that is returned. The first character from the left in the method object string is always 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, name required, parameter that specifies the character used to pad the result string on the right, if it is shorter than the requested length. Pad defaults to the 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.


  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