Some Code Analyze

[Dr XJ]

Hello,
as the forums says, I'm a beginner at C++ coding.
I Have two questions.

Please tell me what this code does. thanks. I need to describe the code to someone.

list(int shomareParvaz1,string mabda1,string maghsad1,int gheimat1,list *next1=NULL){
		mabda=mabda1;
		maghsad=maghsad1;
		shomareParvaz=shomareParvaz1;
		gheimat=gheimat1;
		next=next1;
	}

And my second question is, I have a warning with this code!

 if(next != NULL){
			 prive -> next = next->next; //This line
		delete next;
		system("cls");
        cout << " \n \t Succesfully Removed \n"<<endl;
		system("Pause");
		system("cls");
	}

Thanks in advanced!
And this is my whole source code, just in case.

By the way, is there any other way to write this easier and better?

#include <iostream>
#include <string>
using namespace std;
struct list{
    string mabda;
	string maghsad;
	int shomareParvaz;
	int gheimat;
	list(int shomareParvaz1,string mabda1,string maghsad1,int gheimat1,list *next1=NULL){  
		mabda=mabda1;
		maghsad=maghsad1;
		shomareParvaz=shomareParvaz1;
		gheimat=gheimat1;
		next=next1;
	} 
	list *next;
	list *prev;
	list *temp;
	list *tempezafi;



};	list *head;

class flight {
public:
	flight(); // constructor
	~flight();// destructor
	void Add_List(int shomareParvaz, string mabda, string maghsad , int gheimat);
  void Delete1(int shomareParvaz);
  private:
	
};

flight::flight(){
	head=NULL;
}

flight::~flight(){
	list *temp=head;
	while ( temp != NULL ){
		list *tempezafi=temp;
		temp=temp->next;
		delete tempezafi;

	
	}
	
}

void flight::Delete1(int shomareParvaz){
	list *prive;
	if (head==NULL){
		cout<<"List Is Empty"<<endl;
		return;}
	if (head->shomareParvaz==shomareParvaz){
	list *next=head;
	head=head->next;
		delete next;
	
	 system("cls");
     cout <<"\n \t Succesfully Removed \n"<<endl;
	 system("Pause");
	 system("cls");}
	else {
		 list *next = head;
		 while (next != NULL && next->shomareParvaz != shomareParvaz){
			 list *prev = next;
			 next=next->next;
		 }
		 if(next != NULL){
			 prive -> next = next->next; 
		delete next;
		system("cls");
        cout << " \n \t Succesfully Removed \n"<<endl;
		system("Pause");
		system("cls");
	}
	}



		 
}

[strongdrink]

Please tell me what this code does.

I have a feeling that someone is stealing a homework project.

[Dr XJ]

I'm working on Linked List, and this is just a practice I got from a friend of mine.
Someone please answer, I'm short in time. thanks

[ThangDo]

You can think of

list(int shomareParvaz1, 
	 string mabda1, 
	 string maghsad1, 
	 int gheimat1, 
	 list *next1=NULL)
{
	mabda = mabda1;
	maghsad = maghsad1;
	shomareParvaz = shomareParvaz1;
	gheimat = gheimat1;
	next = next1;
}

as a constructor where you pass in data to populate the structure. That's all this function does.

if(next != NULL)
{
	prive->next = next->next; //This line
	delete next;
	system("cls");
	cout << " \n \t Succesfully Removed \n" << endl;
	system("Pause");
	system("cls");
}

probably that's where you get the warning. If you have the full warning, it will be useful.

[Dr XJ]

Thank you very much ThangDo.

here is the warning:
" warning C4700: uninitialized local variable 'prive' used"

We didn't used private. is there a problem?

#include <iostream>
#include <string>
using namespace std;
struct list{
    string mabda;
	string maghsad;
	int shomareParvaz;
	int gheimat;
	list(int shomareParvaz1,string mabda1,string maghsad1,int gheimat1,list *next1=NULL){ 
		mabda=mabda1;
		maghsad=maghsad1;
		shomareParvaz=shomareParvaz1;
		gheimat=gheimat1;
		next=next1;
	} 
	list *next;
	list *prev;
	list *temp;
	list *tempezafi;



};	list *head;

class flight {
public:
	flight(); // constructor
	~flight();// destructor
  void Delete1(int shomareParvaz);
  private:
	};

[Moschops]

We didn't used private prive. is there a problem?

Yes you did. In the following code, the lines to care about are the first and the last.

list *prive;
	if (head==NULL){
		cout<<"List Is Empty"<<endl;
		return;}
	if (head->shomareParvaz==shomareParvaz){
	list *next=head;
	head=head->next;
		delete next;
	
	 system("cls");
     cout <<"\n \t Succesfully Removed \n"<<endl;
	 system("Pause");
	 system("cls");}
	else {
		 list *next = head;
		 while (next != NULL && next->shomareParvaz != shomareParvaz){
			 list *prev = next;
			 next=next->next;
		 }
		 if(next != NULL){
			 prive -> next = next->next; 

In the first line, you create a pointer, and you give it no value. So it will have some random value. It will be poitning into some random piece of memory somewhere.

In the last line, you write a value ( next->next ) into wherever prive is pointing! It's just some random memory somewhere. You could be writing over the top of data, or you could cause a segFault. This is very bad.

[Dr XJ]

Thanks a lot dear Moschops.

=====================
Is there any other thing necessary? I made every functions public, and private is empty. should I put anything in Private?