Thread: Preprocessor directives

  1. 10-28-2010 #1
    Sonia
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    Preprocessor directives

    hey guys i came across this

    Code:
    #define LCD_E(x)              ((x) ? (IOSET1 = PIN_E)  : (IOCLR1 = PIN_E) );
    i know that it is macro expansion but wat does the expression in the brackets mean?
  2. 10-28-2010 #2
    laserlight
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    It is the ternary operator. If x evaluates to true, the result of the operation is (IOSET1 = PIN_E), otherwise it is (IOCLR1 = PIN_E). Incidentally, the semi-colon at the end of the macro looks like it should not be there.
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  3. 10-28-2010 #3
    Prelude
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    On a completely unrelated note:

    [] = Brackets
    {} = Braces
    () = Parens (parentheses)

    As it is, one can figure out what you meant, but saying "brackets" when you mean "parens" can be confusing if both are present in the expression.
    My best code is written with the delete key.
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