Exercises for Beginners 1

[1v5E3TCk]

Hello, everyone.
I am here for sharing exercises with posible solutions with them.

If you have any other solutions for my exercises or you have new exercises share them on this topic. I will start to share in 1 hour. Thanks

[1v5E3TCk]

Ask the user for two users' ages, and indicate who is older;

1. Solution:

#include <iostream>
#include <string>

using namespace std;

int main()
 {
    int firstage;  // an integer for storing first user's age
    int secondage; //  an integer for storing second user's age
 
    string firstname; // a string for storing first user's name
    string secondname; // a string for storing second user's name
 
    cout<<"Input first user's name"<<endl;  // ask for first user's name
    getline( cin, firstname );      // and store the name as first
 
   cout<<"Input second user's name."<<endl;  // ask for second user's name
    getline(cin, secondname);   // and store the name as second

    cout<<"Input "<<firstname<<"'s age"<<endl; // ask for first user's age
    cin>>firstage;   // and store the age as first.age

    cout<<"Input "<<secondname<<"'s age"<<endl; // ask for second user's age
    cin>>secondage;  // and store the age as second.age

// compare first user's age and second user's age

    if (firstage<secondage){cout<<secondname<<" older than "<<firstname;}  

    else if (firstage==secondage) {cout<<firstname<<"'s and "<<secondname<<"'s age are same.";}

    else {cout<<firstname<<" older than "<<secondname<<endl;}
    system("pause");
    
    }

    

2.Solution with structures (Thanks for Vlad From Moscow):

#include <iostream>
#include <string>
#include <cstdlib>

using namespace std;

int main() 
{
   struct Person
   {
      std::string name;
      size_t age;
   } first, second;

    cout << "Input first user's name: ";
    getline( cin, first.name );

    cout << "Input second user's name: ";
    getline( cin, second.name );

    cout << "Input " << first.name << "'s age: ";
    cin >> first.age;

    cout << "Input " << second.name << "'s age: ";
    cin >> second.age;

    if  ( first.age < second.age ) 
    {
        cout << second.name << " older than " << first.name;
    }  
    else if ( first.age == second.age ) 
    {
        cout << first.name << "'s and " << second.name <<"'s age are same.";
    }
    else 
    {
        cout << first.name << " older than " << second.name;
    }
    
    cout << endl;

    system( "pause" );
}

[vlad from moscow]

As an age can not be negative I think it would be better to declare x and y as unsigned int.

[vlad from moscow]

Also take into account that blank lines in the code are very important for its formatting and reading.
For example instead of

    int x;  // an integer for storing first user's age
    int y; //  an integer for storing second user's age
    string first; // a string for storing first user's name
    string second; // a string for storing second user's name
    cout<<"Input first user's name"<<endl;  // ask for first user's name
    getline( cin, first );  

it would be much better to write at least

    int x;  // an integer for storing first user's age
    int y; //  an integer for storing second user's age
    string first; // a string for storing first user's name
    string second; // a string for storing second user's name

    cout<<"Input first user's name"<<endl;  // ask for first user's name
    getline( cin, first );  

Also never use this style pf placing braces

int main() {

It is simply a very bad style.

[vlad from moscow]

And instead of variables x and y it would be better to name them something derived from word age.:)

[1v5E3TCk]

thanks for comments but i think no one will input a negative age so it is not a problem.

and for the second comment i will correct them

[vlad from moscow]

I would declare a structure something as

int main()
{
   struct Person
   {
      std::string name;
      size_t age;
   } first, second;

// some stuff

   if ( first.age < second. age )
   {
      cout << second.name << " older than " << first.name;
   }  

It is more readable than simple x, y first, second.:)

[1v5E3TCk]

I still dont know structure and i am still a beginner so i am sharing the codes which i can understand. But if you share all the code using structure i can it as second solution

[vlad from moscow]

Or maybe even the following way

int main()
{
   struct Person
   {
      std::string name;
      size_t age;
      bool operator <( const Person &p ) const { return ( age < p.age ); }
      bool operator ==( const Person &p ) const { return ( age == p.age ); }
   } first, second;

// some stuff

   if ( first < second )
   {
      cout << second.name << " older than " << first.name;
   }  

[1v5E3TCk]

Deleted...

[vlad from moscow]

Without testing. So the code can contain a typo.

#include <iostream>
#include <string>
#include <cstdlib>

using namespace std;

int main() 
{
   struct Person
   {
      std::string name;
      size_t age;
   } first, second;

    cout << "Input first user's name: ";
    getline( cin, first.name );

    cout << "Input second user's name: ";
    getline( cin, second.name );

    cout << "Input " << first.name << "'s age: ";
    cin >> first.age;

    cout << "Input " << second.name << "'s age: ";
    cin >> second.age;

    if  ( first.age < second.age ) 
    {
        cout << second.name << " older than " << first.name;
    }  
    else if ( first.age == second.age ) 
    {
        cout << first.name << "'s and " << second.name <<"'s age are same.";
    }
    else 
    {
        cout << first.name << " older than " << second.name;
    }
    
    cout << endl;

    system( "pause" );
}

The program is selfdocumented so it needs no comments. Though you can place a general comment before main.

[1v5E3TCk]

working fine

[vlad from moscow]

It would be better if one thread will correspond to one your exercise.

[1v5E3TCk]

thanks for your comment i will do it

[vlad from moscow]

The first your solution will not be compiled. You may not declare such identifies as (with embedded point)

int first.age; // an integer for storing first user's age
int second.age; // an integer for storing second user's age

string first.name; // a string for storing first user's name
string second.name; // a string for storing second user's name

[1v5E3TCk]

is the problem "." ?

[chipp]

@vlad:

system( "pause" );

you use system()?

[1v5E3TCk]

is it matter?

[chipp]

yes

reference:
http://www.cplusplus.com/forum/articles/11153/

[1v5E3TCk]

what i can i use instead of system()? cin.get()?