qp.hlp (Table of Contents; Topic list)
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Empty Statement
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  Description
 
    An empty statement exists whenever the Pascal syntax indicates
    that a statement could exist but doesn't. Given this condition,
    the compiler inserts an empty statement into the program. The
    empty statement is a null action. Some empty statements are
    harmless, but others are fatal. The following example illustrates
    a harmless empty statement:
 
       BEGIN
       <statement>;
       <statement>;
       END
 
    Because semicolons separate statements, the compiler inserts an
    empty statement to follow the second semicolon. In this case, the
    empty statement is harmless. It even prevents a common programming
    error if another statement is added to the end of the block.
 
    The following example illustrates a subtle bug introduced by an
    empty statement:
 
       IF input_incorrect THEN;
           get_input;
 
    The intent of get_input is obvious to a programmer; however, the
    compiler understands the semicolon after THEN to indicate an empty
    statement. To QuickPascal, this example means: if input_incorrect,
    then do nothing; now get_input.