CODEWITHSUNDEEP
c++
anjanik012
anjanik012

Reputation: 189

How to break the loop using user input?

I am trying something like this.Its counting down seconds from 5-1.

 #include<iostream>
 #include<stdlib.h>
 #include<windows.h>
 #include<iomanip>
 using namespace std;

 int main()
 {
    for(int i=5;i>0;i--)
  {
   cout<<"\n\n\n\n\n\n";
   cout<<setw(35);
   cout<<i;
   Sleep(1000);
   system("CLS");
  }
  system("PAUSE");
}

And i trying to figure out a way to break the loop using a user input(from keyboard) to break it while its running. I have no idea about how to do this.I have heard about multi-threading. I don't even know if multi-threading has any application in my situation or not .So any ideas on how to break it in middle while its executing the loop?

Upvotes: 1

Views: 4745

Answers (2)

LKW
LKW

Reputation: 180

I think you will need a thread to do it.

add a global variable in your main loop, use a thread to receive the command line input and modify your global variable.

declare a global variable

bool stop = false;

create a thread to read stdin and modify 'stop'

DWORD WINAPI thread1(LPVOID pm)
{
    //check the getchar value
    int a = getchar();
    while (a != '0'){
        a = getchar();
    }
    stop = true;
    return 0;
}

in your main:

HANDLE handle = CreateThread(NULL, 0, thread1, NULL, 0, NULL);
 for(int i=5;i>0 && !stop;i--)
  {
   cout<<"\n\n\n\n\n\n";
   cout<<setw(35);
   cout<<i;
   Sleep(1000);
   system("CLS");
  }

Upvotes: 1

Sagar Patel
Sagar Patel

Reputation: 852

  • Try this: 

    #include<iostream>
using namespace std;
int main()
{
   int i = 1;
   while(i)
   {
     // do your work here
     cin>>i;
   } 
   cout<<"Terminated"<<endl;
}

    Continue scanning int i, when you want to break loop give 0 as input value and your loop will be terminatd.

Upvotes: 0

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