help me with pop function!!

[fresh quail]

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[real dove]

!howto ask

[visual lynx]

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[waxen ivy]

could you show code?

[real dove]

    {
        if (y == nullptr)
        {
            return -128;
        }
        else 
        {   
            return -1
        }
    }

int main(){
        signed char x[100];
        signed char* y = x;
        return 0
}```

im still a beginner

[thorn atlas]

this does not compile

[real dove]

yea

still working on it

[thorn atlas]

what is the data structure that holds the elements you are storing

how are elements added a.k.a. push-ed

and how are they poped?

[real dove]

im trying to write stack pop from scratch

how pop remove the last element of the array

thats what im trying to do

[thorn atlas]

are you writing in C, or C++ ?

[real dove]

c++

[thorn atlas]

do you know how to write classes?

[real dove]

not really

i can try

[thorn atlas]

do you know what a class is and what it is used for in C++ ?

[real dove]

class Stack {
    public:
    signed char pop(void) 
    {
        if (y == nullptr)
        {
            return -128;
        }
        else 
        {   
            return -1
        }
    }    
    private:
        signed char x[10];
        signed char* y = x;

};```

[real dove]

store stuff and can use for function?

[thorn atlas]

well, yea

explain to me in english, what fields does the stack class need in order to track the elements stored in it?

you have a signed char of 10 elements

a.k.a. the actual storage

and what else do you need?

[real dove]

im not a english speaker btw

[thorn atlas]

what is signed char* y used for here?

[real dove]

pointer the first element

[thorn atlas]

so you use is to track which element is on the top of the stack?

[real dove]

yes

then remove the top or last element

[thorn atlas]

what is the value of y when your stack is empty?

[real dove]

back to first element?

so -1

[thorn atlas]

what is the type of the field y ?

a number?

[real dove]

Character

thats why i use char

[thorn atlas]

that is not true

the type of the variable y is a pointer to signed char

change it to int elementCount please

[real dove]

class Stack {
    public:
    int pop(void) 
    {
        if (elementCount == nullptr)
        {
            return -128;
        }
        else 
        {   
            return -1
        }
    }

    
    private:
        int x[10];
        int elementCount = x;

};```

[thorn atlas]

leave elementCount uninitialized

create a constructor with zero parameters and in there initialize elementCount to zero, a.k.a. empty stack

[real dove]

uninitialzied?

im confused what u mean

[thorn atlas]

class Stack {
    public:
    int pop(void) 
    {
        //TODO
    }

    Stack()
    {
      this->elementCount = 0;
    }

    
    private:
        int x[10];
        int elementCount;

};

[real dove]

i dont want to use stack()

i want to write it in scratch

[thorn atlas]

I am writing it from scratch

[real dove]

oh okay

now what should we do now

[thorn atlas]

create two functions, push and pop

push adds one element, pop removes one element

[real dove]

let do pop first

[thorn atlas]

void pop()
{
  if(this->count == 0)
  {
    --elementCount;
  }
  else
  {
    cout<<"error - stack is empty\n";
    exit(1)
  }
}

void push(int element)
{
  if(count == 10)
  {
    cout<<"error: stack is full\n";
    exit(1);
  }
  else
  {
    this->x[this->elementCount] = element;
    this=>elementCount++;
  }
}

[real dove]

im confused

i though u cant do void function in class

[thorn atlas]

any function can use the return type void

including member functions inside a class

[thorn atlas]

which line

class Stack {
    public:

    Stack()
    {
      this->elementCount = 0;
    }

    void pop()
    {
      if(this->count != 0)
      {
        --elementCount;
      }
      else
      {
        cout<<"error - stack is empty\n";
        exit(1)
      }
    }

    void push(int element)
    {
      if(count == 10)
      {
        cout<<"error: stack is full\n";
        exit(1);
      }
      else
      {
        this->x[this->elementCount] = element;
        this=>elementCount++;
      }
    }
    private:
        int x[10];
        int elementCount;

};