C++ increment decrement operators

C++ increment decrement operators

1. Write a C++ program to produce the output as shown below: Contents of x               Expression        Value of                Content... 10:21 AM

1. Write a C++ program to produce the output as shown below:

Contents of x               Expression        Value of                Contents of x

before                                                Expression                   after

5                 |                  x++             |         5                 |         6

5                 |                  x--               |         5                 |         4       

5                 |                  ++x             |         6                 |         6  

5                 |                  --x               |         4                 |         4

Solution:

#include <cstdlib> 
#include <iostream> 
  using namespace std; 
int main(int argc, char *argv[]) 
{ 
    int x; 
   x=5;

    cout<<"Contents of x\t"<<"Expression\t"<<"Value of\t"<<"Contents of x\n";

    cout<<"before\t\t\t\t"<<"Expression\t"<<"after\n";
    cout<<"\n";

    cout<<x<<"   |\t"<<"x++"<<" |\t\t\t"<<x<<"\t"<<"\t|"<<"x="<<x+1<<"\n";

    cout<<x<<"   |\t"<<"x--"<<" |\t\t\t"<<x<<"\t"<<"\t|"<<"x="<<x-1<<"\n";

    cout<<x<<"   |\t"<<"++x"<<" |\t\t\t"<<x+1<<"\t"<<"\t|"<<"x="<<x+1<<"\n";

    cout<<x<<"   |\t"<<"--x"<<" |\t\t\t"<<x-1<<"\t"<<"\t|"<<"x="<<x-1<<"\n";
      system("PAUSE");
    return EXIT_SUCCESS;
}

2. Write a program to prompt the user to input the integral value of a and print out the result as shown below:

Result: 
The value of a is: 10 
…………………….. 
The value of ++a is: 11 
Now the value of a is: 11 
The value of a++ is: 11 
Now the value of a is: 12 
The value of --a is:11 
Now the value of a is:11 
The value of a-- is: 11 
Now the value of a is: 10

Solution:

#include <cstdlib> 
#include <iostream> 
  using namespace std; 
 int main(int argc, char *argv[]) 
{ 
    int a; 
    cout<<"Enter a value:"; 
    cout<<"The value of a is:"<<a; 
    cout<<"\n----------------\n"; 
    ++a; 
    cout<<"\nThe value of ++a is:"<<a; 
    cout<<"\nThe value of a is:"<<a; 
        cout<<"\nThe value of a++ is:"<<a; 
    a++; 
    cout<<"\nThe value of a is:"<<a; 
    --a; 
    cout<<"\nThe value of --a is:"<<a; 
    cout<<"\nThe value of a is:"<<a; 
    cout<<"\nThe value of a-- is:"<<a; 
    a--; 
    cout<<"\nThe value of a is:"<<a; 
    cout<<"\n";     system("PAUSE"); 

    return EXIT_SUCCESS;

}