sizeof trouble

[BasV]

Hi everyone,

I made a little piece of code that generates a random name for my window, but I have some unexpected behaviour. This is the code:

srand(time(NULL));
	char* s1, * s2, * s3;
	char* s1_options[] = {"a", "b", "c", "d", "e"};
	char* s2_options[] = {"1", "2", "3", "4", "5", "6"};
	char* s3_options[] = {"more", "options", "etc"};

	s1 = s1_options[rand() % (sizeof(s1_options) / sizeof(char*))];
	s2 = s2_options[rand() % (sizeof(s2_options) / sizeof(char*))];
	s3 = s3_options[rand() % (sizeof(s3_options) / sizeof(char*))];

	char b[201];
	sprintf(b, "%s: %s to the %s", s1, s2, s3);
	b[200] = 0;
        std::string result = std::string(b);

Usually, I get the results I expected: Output like "a: 1 to the more" or "d: 5 to the etc". However, sometimes I get stuff like:
"ab: 3 to the options".

How can this happen? Cheers!

[Peter87]

How do you print the string? Are you sure the extra character comes from printing the string result?

[BasV]

Oh my, just found out what caused the problem:

I had missed a comma in one of my arrays:

{"a", "b", "c", "d" "e"};

I would have thought this would cause a compiler error but apparantly it's fine?

Sorry for wasting anyone's time :|

Cheers!

[Peter87]

It's an old feature that C++ inherited from C.