3. Program that should allow the user to type up to six digits, and then display the resulting number as a type long integer.

Chapter 3: 

Loops and Decisions

Programming Exercise

Problem # 3:

Operators such as >>, which read input from the keyboard, must be able to convert a series of digits into a number. Write a program that does the same thing. It should allow the user to type up to six digits, and then display the resulting number as a type long integer. The digits should be read individually, as characters, using getche(). Constructing the number involves multiplying the existing value by 10 and then adding the new digit. (Hint: Subtract 48 or ‘0’ to go from ASCII to a numerical digit.)

Here’s some sample interaction:
Enter a number: 123456
Number is: 123456

Solution:

#include <iostream>
using namespace std;
#include <conio.h>
int main()
{
    char a,b,c,d,e,f;
    int num;
  
    cout<<"Enter a number: ";
    a=getche();
    b=getche();
    c=getche();
    d=getche();
    e=getche();
    f=getche();
  
    num=(int)a-48;
    num=num*10+((int)b-48);
    num=num*10+((int)c-48);
    num=num*10+((int)d-48);
    num=num*10+((int)e-48);
    num=num*10+((int)f-48);
  
    cout<<endl<<"Number is: "<<num;
  
    return 0;
}

Let me know in the comment section if you have any question.

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