c++ pointer simple example pass by reference

Write a program which passes a reference to a function and function has a pointer as argument. Keep the return type void and display result in main body. Apply any maths operation find square of a number
Use any c++ compiler: Codeblocks recommended.

If you have any confusion read this difference b/w pass by value and pass by reference 

#include<iostream>
using namespace std;

void pass_by_reference(int *);
int main()
{
    int number;

    cout<<"Enter Number to Calculate Square: ";cin>>number;
    cout<<"\n\n\n";

    pass_by_reference(&number);
    cout<<"\t\tResult: "<<number<<endl;

    return 0;

}

void pass_by_reference(int *iPtr)
{
    *iPtr=*iPtr * *iPtr;
}

Sample input Output of program

In the above example there is no need to return from function because changes will be made permanently on reference of number.
Find more examples here: C++ Simple Examples 

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Differ pass by value and reference c++ example

Pass by value in C++ Programming
In this method we call a function by passing a value. A new copy of value is made and send to functions body. Where operations are applied on new copied value.




Advantages

• New copy is made of value after passing so if changes go wrong the original data will be save
• It increase the security of data

Disadvantage

• If the data is huge making too much copies may cause system over head.

Pass by reference in C++ Programming

In this method we call a function by its reference using address operator. It don't make a copy of data and pass the address of value to the function. Where operations are applied on the reference of value and changes made permanently to data.

Advantages

• When data is large it reduce the copies of data and creates less system overhead.

Disadvantage

• Security of data can be weak because the real information is accessible and can be changed 

C++ function example of both ways pass by value and pass by reference

In this example there are two functions one calculates a cube of number with value and other calculates cube of number with reference. With value returns result and with reference not return result.

#include<iostream>
using namespace std;

int pass_Value(int);
void pass_reference(int &);
int main()
{
    int num1,num2;

    cout<<"Enter First Number: ";cin>>num1;
    cout<<"Enter Second Number: ";cin>>num2;

    cout<<"\n\n\n";

    int result=pass_Value(num1);
    cout<<"\t\tPass By Value Result: "<<result<<endl;

    pass_reference(num2);
    cout<<"\t\tPass By Reference Result: "<<num2<<endl;

    return 0;

}

int pass_Value(int number)
{
    return (number*number*number);
}

void pass_reference(int &number)
{
    number=number*number*number;
}

Read also: C++ pointer example with pass by reference

Input Output Example:

see also: Learn Pointers in C++ Programming with Examples


Explanation of functions

• First function is simple we received a value calculate its cube and return simply the new result.
• In second function we applies changes using reference of number we sent so no need to return here. As changes are made permanently.

See More Examples Here: C++ Simple Examples

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