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Removing comments by the C pre-processor

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• Comments in C

  • It used to be that C only have multi-line comments enclosed between the pairs of "brackets" /* ... */:

    /* ..... ..... ..... */

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  • Examples:

    /* This is a comment in a C program */ /* * This is an another comment * in a C program */

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  • A later revision C99 in 1999 of the C programming language has added the C++ style comment:

    // This is now allowed as comment

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  • The C pre-processor will remove all comments.

    Demo:

    Compile this program comment.c: /* --------------------- Comment line 1 Comment line 2 --------------------- */ int main(int argc, char * argv[] ) { // Comment line 3 } using this command: gcc -E comment.c

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  • Result:

    int main(int argc, char * argv[] ) { }

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  • Example Program: (Demo above code)                                                
    • Prog file: /home/cs255001/demo/c/Cprep/comment.c

    How to run the program:

    To compile:   gcc -E comment.c Look at the output on the terminal....