Reference Variables and Typecasting in C++

 #include<iostream>

using namespace std;

int c = 45;

int main()

{

    // *****************Build in Data types******************

    int a, b, c;

    cout<<"Enter the value of a : "<<endl;

    cin>>a;

    cout<<"Enter the value of b : "<<endl;

    cin>>b;

    c = a + b;

    cout<<"The Sum is : "<<c<<endl;

    //  To take the value of Global variable, scope resolution operator :: is used

    //  5as shown below :

    cout<<"The Global value is : "<<::c<<endl;

    //************ Float, double and long double Literals ****************

    float d = 34.4;

    long double e = 34.4;

    cout<<"The value of d is : "<<d<<endl<<"The value of e is : "<<e<<endl;

    cout<<endl;

    // By default 34.4 is considered as double but if we denote as 34.4f then only it

    //will considered as float value

    cout<<"The Size of 34.4 is "<<sizeof(34.4)<<endl;   //Double value

    cout<<"The Size of 34.4f is "<<sizeof(34.4f)<<endl; //Float value

    cout<<"The Size of 34.4F is "<<sizeof(34.4F)<<endl; //Float value

    cout<<"The Size of 34.4l is "<<sizeof(34.4l)<<endl; //Long double value

    cout<<"The Size of 34.4L is "<<sizeof(34.4L)<<endl; //Long double value

    cout<<endl;

    //***************** Reference Variables ********************

    float x = 32;   //Here variable is only one but there are like multiple names

    float & y = x;  //Here the value of x will be passed to the value of y

    cout<<x<<endl;

    cout<<y<<endl;

    cout<<endl;

    //***************** Typecasting *******************

    //Typecasting means changing one variable Data Type to another Data Type

    int m = 45;

    float n = 56.32;

    double v = 89.21;

    cout<<"The value of a is : "<<(float)m<<endl;

    cout<<"The value of a is : "<<float(m)<<endl;   //Both are same as above

    cout<<"The value of b is : "<<(int)n<<endl; //Here value is converting from float to integer

    cout<<"The value of b is : "<<int(n)<<endl; //Both are same as above

    cout<<"The value of v is : "<<(int)v<<endl;//Here value is converting from double to integer

    cout<<"The value of v is : "<<int(v)<<endl; //Both are same as above

    int v2 = int(n);    // Assigning value of n into variable v2

    cout<<"The value of v is : "<<int(v2)<<endl;

    cout<<endl;

    cout<<"The Expression is : "<<m + n<<endl;

    cout<<"The Expression is : "<<m + int(n)<<endl;

    cout<<"The Expression is : "<<m + (int)n<<endl;

}

//OUTPUT:

// Enter the value of a :

// 55

// Enter the value of b :

// 55

// The Sum is : 110

// The Global value is : 45

// The value of d is : 34.4

// The value of e is : 34.4

// The Size of 34.4 is 8

// The Size of 34.4f is 4

// The Size of 34.4F is 4

// The Size of 34.4l is 12

// The Size of 34.4L is 12

// 32

// 32

// The value of a is : 45

// The value of a is : 45

// The value of b is : 56

// The value of b is : 56

// The value of v is : 89

// The value of v is : 89

// The value of v is : 56

// The Expression is : 101.32

// The Expression is : 101

// The Expression is : 101