* The [[STRING]] return value is anything typed after a program's executable file name in command line (or using the [[RUN]] statement).
* Unlike QuickBASIC, '''QB64''' does not return all [[UCASE$|uppercase]] values so keep that in mind when checking parameters.
* In '''QB64''', COMMAND$ works as an array to return specific elements passed to the command line. COMMAND$(2) would return the second parameter passed at the command line. Arguments can contain spaces if they are passed inside quotation marks. This can be used to properly retrieve file names and arguments which contain spaces.
* Use the [[_COMMANDCOUNT]] function to find the number of parameters passed to a program via the command line. See ''Example 2'' below.
: ''Explanation: If we start ''ThisProgram.exe'' with the command line '''ThisProgram -l "a data file"''', COMMAND$ will return a single string of "-1 a data file" which might be hard to process and interpret properly, but COMMAND$(1) would return "-l" and COMMAND$(2) would return the quoted "a data file" option as separate entries for easier parsing and processing.
''Example 3:'' As part of the command array syntax, you can also just read the array to see how many commands were sent (or simply check [[_COMMANDCOUNT]]):