Heres a neat trick for checking whether two strings are equal: if(!strcmp(s1, s2)) Is this good style?
It is not particularly good style, although it is a popular idiom. The test succeeds if the two strings are equal, but the use of ! (“not”) suggests that it tests for inequality. Another option is to define a macro: #define Streq(s1, s2) (strcmp((s1), (s2)) == 0) which you can then use like this: if(Streq(s1, s2)) Another option (which borders on preprocessor abuse; see question 10.2) is to define #define StrRel(s1, op, s2) (strcmp(s1, s2) op 0) after which you can say things like if(StrRel(s1, ==, s2)) … if(StrRel(s1, !=, s2)) … if(StrRel(s1, >=, s2)) … See also question 17.10. comp.lang.c FAQ list ยท Question 17.4 Q: Why do some people write if(0 == x) instead of if(x == 0)? A: It’s a trick to guard against the common error of writing if(x = 0) If you’re in the habit of writing the constant before the ==, the compiler will complain if you accidentally type if(0 = x) Evidently it can be easier for some people to remember to reverse the test than to remember to type the doubled
