Thread: Subtraction in C

  1. #1
    Registered User
    Join Date
    Feb 2012

    Subtraction in C

    i am little confused with subtraction
    #include <stdio.h>
    int main(void)
      unsigned char test1;
      unsigned char test2;
     if(test1 - test2 > somevalue)
      // Take some action
    The values test1, test2 can change dynamically and sometimes test2 is greater than test1. My doubt is if(test1 - test2 > somevaue) is correct way of writing and works for any value of test1 and test2?


  2. #2
    Master Apprentice phantomotap's Avatar
    Join Date
    Jan 2008

    You should search for "C Operator Precedence".

    If you find the expression confusing, you can always add extra (`(test1 - test2) > somevalue') parentheses.

    You can pretty easily overdo extra grouping with parentheses, but you should be fine explicitly grouping expressions you find semantically ambiguous because you don't know the precedence rules by heart.

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