03.conditional statements in c++

1.If Statement

it is a conditional statement.. The if statement is used to execute the code, only when a condition is true.

if (test condition) 

{ 

block statement

}



Example- checking if a number is greater than 100


#include<iostream>
using namespace std;
int main ()

{
 int a;

   cout<<"enter the number \n" ;
        cin>>a;


    if (a>100)
    {
        cout<<"yes, the number is greater than 100" ;
    }

    return 0;
}

similarly you can use

>=       greater than or equal to 
<=       less than or equal to
==        equal to


!=        not equal to

---

Example- checking the greater number out of two

#include<iostream>
using namespace std;
int main ()

{
    int a;
    int b;

    cout<< "enter a number a\n" ;
    cin>>a;

    cout<<"enter another number b\n" ;
    cin>>b;

    if (a>b)
    {
        cout<<"a is greater than b";
    }


    if (b>a)
    {
        cout<<"b is greater than a" ;
    }


    if (b==a)
    {
        cout<<"both are equal" ;
    }

    return 0;

}

---

2.If-Else Statement

if (test condition)

{block statement}

else

{statement}



Example-  fail/pass in an exam

#include<iostream>
using namespace std;
int main ()

{

    int marks;


    cout<<"enter your marks"<<endl ;

    cin>>marks;


    if(marks<33)

    {
        cout<<"failed";
    }

            else
            {
             cout<<"passed"<<endl;
             cout<<"congratulations"<<end;
             }



    return 0;
}

---

3.Nested If Statements

Example -.  fail/pass in an exam

#include<iostream>
using namespace std;
int main ()


{
    int age;

    cout<<"enter your age" ;
    cin>>age;

    if( age>14)

        {

                if (age>=18)
                 {
                cout<<"adult" ;
                  }


                else
                    {
                    cout<<"teenager";
                    }

          }

return 0;

}

the above program wont give any output for age less than 14...
for that, you will need another else statement.


4.Nested If-Else Statements

Example -adult/teenager 

#include<iostream>
using namespace std;
int main ()

{
    int age;
    cout<<"enter ur age \n" ;
    cin>> age;

    if( age>=13)

        {
                    if (age>=18)
                     {
                    cout<< "adult" ;
                      }

                         else
                        {
                         cout<<teenager";
                         }
          }


          else { cout<<"you are a kid";}

return 0;

}

In the next blog,you will get to learn about loops.