CODEWITHSUNDEEP
c++classpointersstdvector
allene50
allene50

Reputation: 33

Why is the std::vector not giving any outputs in c++

I don't understand why but the std::vector is not giving anything after i put a class pointer in the array.

// runs at start
void States::AssignState(GameState* state) {
    _nextVacentState++;
    _states.push_back(state);
}

// executes in a loop
void States::ExecuteCurrentState() {
    // protection incase there is nothing in the array or the current state is not grater than the size of the array (not the problem after i nerrowed the problem down)
    if (_nextVacentState == 0) std::cout << "Error: There is no states, setup some states then try again" << std::endl; return; // there is no states
    if (_currentState >= _states.size() - 1) std::cout << "Error: Current State is grater than all possable states" << std::endl; return;
    
    // The program just freezes at this and i can figure out why
    _states[0]->tick();
    std::printf("S");
}

Upvotes: 0

Views: 87

Answers (1)

Nathan Pierson
Nathan Pierson

Reputation: 5565

This is one of the reasons I'd suggest getting in the habit of using curly braces for all if statements, even ones that live on a single line.

A problem line:

if (_nextVacentState == 0) std::cout << "Error: There is no states, setup some states then try again" << std::endl; return;

Let's add some newlines to make it clearer what's happening

if (_nextVacentState == 0) 
  std::cout << "Error: There is no states, setup some states then try again" << std::endl; 
  return;

That return statement is getting executed unconditionally, because only the first statement after if(_nextVacentState==0) is actually part of the if. So the compiler executes it as if it had been written like this:

if (_nextVacentState == 0)
{
  std::cout << "Error: There is no states, setup some states then try again" << std::endl; 
}
return;

But, what you want needs to be written like this instead:

if (_nextVacentState == 0) 
{
  std::cout << "Error: There is no states, setup some states then try again" << std::endl; 
  return;
}

You have same problem in the next if check for _currentState, as well.

Upvotes: 7

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