Question

Explain Parameter passing Semantics in Java/C++

Answer 1

There are two type or parameter passing semantics in java/c++

1. Pass by value

2. Pass by reference

1) Pass by value :- In the pass by value the original data are not modified, it will just copy the data which we will pass.

For example:-

#include <iostream>
using namespace std;
void pass(int value) {
cout << "Value passed by parameter into function: " << value << endl;
value = 20;
cout << "Value before function end: " << value << endl;
}
int main() {
int value = 10;
cout << "Value before calling : " << value << endl;
pass(value);
cout << "Value after calling: " << value << endl;
return 0;
}

/******************output**********************/

Value before calling : 10
Value passed by parameter into function: 10
Value before function end: 20
Value after calling: 10

--------------------------------

2) Pass by reference :- It will change the original value of the variable.

For Example:
#include <iostream>
using namespace std;
void process(int& value) {
cout << "Value passed by parameter into function: " << value << endl;
value = 20;
cout << "Value before function end: " << value << endl;
}
int main() {
int value = 10;
cout << "Value before calling : " << value << endl;
process(value);
cout << "Value after calling: " << value << endl;
return 0;
}

/****************output************************/

Value before calling : 10
Value passed by parameter into function: 10
Value before function end: 20
Value after calling: 20

--------------------------------

Please let me know if you have any doubt or modify the answer, Thanks :)