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