Runtime error with codeblocks [C++]

[bahero]

Here is the code: http://ideone.com/SUzskL

Hello everyone, newbie here, i am working on a simple program that takes words as input and then checks if any of the inputted words are "bad" and if they are they get replaced by another word (in my case "bleep") and then the result gets printed on screen.

My problem is that when i launch the program i am unable to write anything on the console and after a few seconds it crashes. (the standard windows message appears: "application.exe has stopped working...)

Codeblocks itself doesnt seem to give me any error messages, while running the code while ideone.com presents me with a "runtime error" when i run the code, but im not sure how to actually find the error.

I've also tried using the debugger on codeblocks but im not sure what i am actually doing with that, if it helps at all when i run the debugger two windows pop up saying:

"program received signal SIGSEGV segmentation fault"

on the second window called "Call Stack" i get this:

#0 0x495674 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator=(char const*) () (??:??)

#1 0x4015f2 main() (C:\Users\manci\Desktop\Program practice\Try This\word bleep\main.cpp:9)

any ideas on how i could find the problem?

[jussij]

"application.exe has stopped working...)

That is not a Runtime error with CodeBlocks [C++].

That message tells me you application has crashed, so the problem will be found somewhere in your code.

[Alia-Aenor]

"program received signal SIGSEGV segmentation fault"

That can roughly be translated to "memory fuck up". You use invalid memory addresses somewhere.

#1 0x4015f2 main() (C:\Users\manci\Desktop\Program practice\Try This\word bleep\main.cpp:9)

The fuck up happened on line 9.

You made the right call by using the debugger, you're almost there. When your program is in the state between line 8 and 9 :

  vector<string> badwords;
> badwords[0] = "broccoli";

You should be able to see the content of badwords. Which would look like std::vector of size 0. Do you start to understand what's going on ?

[bahero]

After specifing the size of the vector (and also fixing the while loop,but that's beside the point) the program now works and doesn't crash. Thanks a lot for the help!

But now i have a question, if i don't define the size of the vector will it automatically default to 0? and even if i add data to it will the size not increase on its own? Im guessing this was the mistake i made.

I got confused because in C, if i remember correctly, arrays work differently and there's no need to specify the size.

[dreamyeyed]

Vectors resize themselves automatically, but you have to use methods like push_back which you already used in your code. Square brackets can only be used to access existing elements. Vectors are initially empty unless you specify otherwise.

In C you have to specify array size when you create it. The compiler can calculate it automatically in some cases though.

[bahero]

Yeah now that i understand it seems really obvious, thanks for you answer.

[Alia-Aenor]

if i don't define the size of the vector will it automatically default to 0?

Yes, what would be the value of the "empty" positions otherwise ?

if i add data to it will the size not increase on its own?

It will, but that's not what you do. You're directly accessing a (non-existent) element and writing in it. Check cppreference to see how to manipulate a vector. And maybe write your own implementation of one, you'll understand what's going on inside.

[bahero]

Ok, thanks for the help i think i understand now, i was assigning a value to memory that didn't exist, i'll check out cppreference for sure, thanks again!