MiniRobotLanguage (MRL)
STR.Reverse
Reverse the Characters in a String
Reverse the order of all characters in a source string.
Intention
The STR.Reverse command reverses the order of all characters in a source string (P1), placing the last character first and the first character last. The result is stored in an optional result variable (P2) or overwrites the source string if P2 is omitted. This command is useful for reversing text or binary data, such as creating palindromes, reversing byte sequences, or processing data in reverse order.
•The entire string is reversed, maintaining its original length.
•The command is safe for binary data, as variables in P1 are resolved only once.
•An empty string remains empty after reversal.
If P1 is empty, the result is an empty string.
Syntax
STR.Reverse|P1[|P2]
Parameter Explanation
•P1 - (Source String) The string to be reversed. Modified directly unless P2 is provided.
•P2 - (Optional Result Variable) The variable to store the reversed string. If omitted, the source string (P1) is overwritten.
Examples
'***********************************
' Example 1: Reverse a string in place
'***********************************
VAR.$$SRC=HelloWorld
STR.Reverse|$$SRC
' $$SRC will contain "dlroWolleH"
MBX.$$SRC
ENR.
'***********************************
' Example 2: Reverse a string to a result variable
'***********************************
VAR.$$SRC=ABC
STR.Reverse|$$SRC|$$RES
' $$RES will contain "CBA"
MBX.$$RES
ENR.
'***********************************
' Example 3: Reverse an empty or single-character string
'***********************************
VAR.$$SRC=
STR.Reverse|$$SRC|$$RES
' $$RES will contain "" (empty string)
MBX.$$RES
VAR.$$SRC=A
STR.Reverse|$$SRC
' $$SRC will contain "A" (single character unchanged)
MBX.$$SRC
ENR.
Remarks
- Variables in the source string (P1) are resolved only once, ensuring safety for binary data (e.g., null characters or special sequences).
- The command is efficient for reversing strings of any length, including large binary data.
- Single-character strings remain unchanged, and empty strings return empty.
- For extracting or manipulating specific parts of a string, consider STR.MidStr, STR.Left, or STR.Right.
Limitations:
- No option to reverse a specific substring; the entire string is reversed.
- No case-insensitive variant available.
See also:
• STR.Left