How Can I Fix Cpp Internal While Loop Error?-CodePudding

I tried to ask int num forever. But didn't work.

#include <iostream>
using namespace std;

int main(){
    int i=0;
    int num;
    int MyArray[]={};
    
    
    while (true) {
        cout<<"sayi giriniz"<<endl;
        cin>>num;
        MyArray[i]=num;
        i  ;
        
        for (int j=0; j<i; j  ) {
            cout<<MyArray[j]<<endl;
        }
        
    }

    return 0;
}

https://imgur.com/a/tANGpSY When I enter the 3rd value it gives a strange reaction

CodePudding user response：

int MyArray[]={};

Now, MyArray has a size of 0, so any indexes that you tried to access MyArray will cause undefined behavior.

If you want to make an array that is dynamically in size, use std::vector in the <vector> header.

Change

int MyArray[]={};

std::vector<int> MyArray;

This:

MyArray[i]=num;
i  ;

To this:

MyArray.push_back(num); // you don't even need i

This

for (int j=0; j<i; j  ) {
    cout<<MyArray[j]<<endl;
}

To this:

for(const auto &i : MyArray) // range based for loop, recommend
{
    std::cout << i << '\n';
}

Also, using namespace std; is bad, so don't use it.

CodePudding user response：

If you want to take input and are unsure about the number of elements, you should use a vector. The array which you have made is of 0 size. It will surely give you an error.