Variables And Input operator in c++

 Variables 

Variable size 

                                                                                                                                       

Variable provides us  to store the data in System with named witch further can manipulate. In C++  Variable has a specific type, which tell the size and layout of the variable's memory. 

Program: write a program to find out the average of two number take input from user using variable  

Code:

#include<iostream>

using namespace std;

int  main()

{

float num1,num2, sum,average;

cout<<"Give two number to find out the average\n";

cout<<"Enter first number:";

cin>>num1;

cout<<"Enter Second number:";

cin>>num2;

sum=num1+num2;

average=sum/2;

cout<<"The average of "<<num1<<" and "<<num2<<" is "<<average;

}

OUTPUT:

Give two number to find out the average

Enter first number:10.6

Enter Second number:12.5

The average of 10.6 and 12.5 is 11.55

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Input operator 

In C++, it's used to take input from user using << . In the above example nun1 and num2 two input take from user. The identifier cin (pronounced 'C in') is a predefined object in C++ that corresponds to the standard input stream. Here , this Stream represents the keyword.

    The operator >> is known as extraction or get from operator. It extracts (or takes ) the value from the keyboard and assigns it to the variable on its right. This corresponds to the familiar scanf() operation, Like <<, the operator >> can also be overloaded 

Program: Write a program to find whether a given number is palindrome or not and take input from user.

Code:

#include<iostream>

using namespace std;

int main()

{

int rev,temp,num,digit=0;

cout<<"Enter a number";

cin>>num;

temp=num;

while(num!=0)

{

digit=num%10;

rev=rev*10+digit;

num=num/10;

}

if(rev==temp)

{

cout<<"The given  number is palindrome ";

}

else 

cout<<"The given  number is  not  palindrome ";

}

OUTPUT:

Enter a number145636541

The given  number is palindrome

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Program: Write a program to find the area of rectangle, square and circle. Taking input as radius length and breath of rectangle, side of square.

Code:

#include<iostream>

using namespace std;

int main()

{

 int  radius, l,b;

 float a;

 cout<<"Enter the radius of circle";

 cin>> radius;

 cout<<"Enter the lenth and brath of rectangle ";

 cin>>l;

 cin>>b;

 cout<<"Enter the side of square ";

 cin>>a;

 cout<<"\nThe area of rectangle is "<<l*b;

 cout<<"\nThe area of square is"<<a*a;

 cout<<"\nThe area of circle is "<<3.14*radius*radius;

}

OUTPUT:

Enter the radius of circle3

Enter the lenth and brath of rectangle 5

6

Enter the side of square 5

The area of rectangle is 30

The area of square is25

The area of circle is 28.26

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