C++ Variables

               A value or data stored in a memory. It is identified using a name. That is called a 'Variable'.

First, a variable should be declared.

The syntax is given below…

              Datatype variable-name;

Eg:

int n;

float a;

double b;

char s[];

bool d;

Next, the variable should be initialised.

‘int n = 5;’

‘float a =3.4;’

‘double b = 5.67;’

‘char s[] = “string”;

‘bool d = true;’

Let us create a sample program to display the customer details using C++

C++ Program:

#include <iostream>

using namespace std;

int main() {

    int  c_age;         // integer variable

    string c_id;;         // character variable

    string c_name; //String

    float c_salary; // float variable

    cout<< "Enter the Customer Name" << endl;

    cin >>c_name;

    cout<< "Enter the id"<<endl;

    cin >>c_id;

    cout<< "Enter the Customer age" <<endl;

    cin >>c_age;

    cout<<" Enter the Customer Salary" <<endl;

    cin >>c_salary;

    cout << "Customer Details" <<endl;

    cout << "Name: " << c_name << endl;

    cout << "Age: " << c_age << endl;

    cout << "Id: " << c_id << endl;

    cout << "Salary: " << c_salary << endl;

    return 0;

}

Output:

Enter the Customer Name

Jeyanth

Enter the id

C1

Enter the Customer age

25

 Enter the Customer Salary

44466.34

Customer Details

Name: Jeyanth

Age: 25

Id: C1

Salary: 44466.3

Note: The scope of the variable can be classified into local, global, static and dynamic.

If a variable holds the constant value, let this program illustrates it…

#include <iostream>

using namespace std;

int main() {

  const float PI = 3.14;

  float r,area =0.0;

  cout <<"Enter the radius"<<endl;

  cin>>r;

  area = PI*r*r;

  cout << "The area of the circle is:"<<area<<endl;

    return 0;

}

The output is given below…

Enter the radius

5

The area of the circle is:78.5

Hope, this code is useful to you to understand variables. Comment your doubts… Keep coding…..