比较以char **形式出现的字符串

Question

int main( int argc, char ** argv ) 
{
   if ( *argv[2] == *argv[3]) { ... }
   return true;
}

It is wrong, isn't it?!

It's not my code, I found it, and, yes, I understand that we should check that we have more than 2 arquments...

Answer 1

For C++, construct std::string from each argument and then compare using operator== .

For C use strcmp .

For both, check argc >= 4 before you do this check.

Answer 2

Try this instead:

#include <string>

int main( int argc, char  ** argv ) 
{
   if (argc >= 4 &&  std::string(argv[2]) == std::string(argv[3])) { ... }
   return 0;
}

Answer 3

Use strcmp , see here:

• http://www.codeguru.com/forum/showthread.php?t=231162

You can use string class for pure C++ if you want, see here:

• http://www.cplusplus.com/reference/string/string/compare/

Answer 4

Yes, it's wrong.

You need strcmp .

Answer 5

It is a perfectly valid code, but it probably doesn't do what you would expect. If condition will be true if argv[2] and argv[3] begin with the same letter because you compare first character of both strings. If you want to compare entire strings use strcmp .

And 2 more advices: When you deal with arguments always check their count (argc). When you exit main thread the standard is to return 0 if everything is fine.