Char Arrays [Solved]

Why is it that storing more then the initilized number or members of an array will not cause problems?

Code:

    char username[16];
    char password[100];
    print("welcome to mc_bot 1.0!");
    printf("username: ");
    scanf("%s", username);

if i enter a username longer then 16 characters, it will still work as normal. WHy?

Look up buffer overflows. Once you exceed 16 bytes it continues writing over whatever memory is after that, which in your case is the bytes for 'password'.

Originally Posted by Void

Look up buffer overflows. Once you exceed 16 bytes it continues writing over whatever memory is after that, which in your case is the bytes for 'password'.

Actually, allocation size is up to the compiler and also depends on the settings, e.g., memory alignment and debug build. So its not certain that the data written will actually overflow into "password", unless you write a ridiculous amount of data.

that makes sense.
I was expected more of a run time error or something that i could visually see

Originally Posted by kibbles18

that makes sense.
I was expected more of a run time error or something that i could visually see

This is very visual, the way you declared your variables alone should be visual enough. Variables are given a name, and all it is is a name. Once in memory it's one big chunk.

Originally Posted by kibbles18

that makes sense.
I was expected more of a run time error or something that i could visually see

C++ doesn't do any runtime checks (though MS have extensions that let you check for this). This is the beauty of C++, in my opinion -- you get to control what happens at a very down-to-Earth manner. Nothing is "assumed" - it does what you tell it to do.

Originally Posted by freedompeace

C++ doesn't do any runtime checks (though MS have extensions that let you check for this). This is the beauty of C++, in my opinion -- you get to control what happens at a very down-to-Earth manner. Nothing is "assumed" - it does what you tell it to do.

Assembly is even more so like this.

Originally Posted by Void

Assembly is even more so like this.

In assembly the code runs you !

(*reads in a Russian accent)

Originally Posted by .::SCHiM::.

In assembly the code runs you !

(*reads in a Russian accent)

Hahahaha! Good laugh!

Char Arrays [Solved]

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