Functions

Use of functions

Functions are set of code wich performs somethig for you
Functions are used to modularised code
Functions are used to increase readability
Functions are used to use same code multiple times

Type of functions

void → which does not return annything
parameterised
non parameterised
return
Pass by Value
Pass by Refrence

Void - Non_Parameterised¶

C++

Void_Function.cpp

#include<bits/stdc++.h>
using namespace std;

void printName() {
    cout << "Akash Singh";
}

int main() {
    printName();
    return 0;
}

Output: Akash Singh

Void - Parameterised¶

C++

Parameterised_Function.cpp

#include<bits/stdc++.h>
using namespace std;

void printName(string name) {
    cout << "Hello " << name;
}

int main() {
    string name;
    cin >> name;
    printName(name);
    return 0;
}

Input: Akash
Output: Hello Akash

Return - Parameterised¶

C++

Return_Function.cpp

#include<bits/stdc++.h>
using namespace std;

int Sum(int num1, int num2) {
    int sum = num1 + num2;
    return sum;
}

int main() {
    int num1, num2;
    cin >> num1 >> num2;
    cout << Sum(num1, num2);
    return 0;
}

Input: 5 6
Output: 11

Pass by Value¶

C++

Pass_by_Value.cpp

#include<bits/stdc++.h>
using namespace std;

void AddFive(int num) {
    cout << "num" << endl;
    num += 5;
    cout << "num" << endl;
    num += 5;
    cout << "num" << endl;
}

int main() {
    int num;
    cin >> num;
    AddFive(num);
    cout << num;
    return 0;
}

Input: 10
Output: 15
20
10

Pass by Refrence¶

C++

Pass_by_Refrence.cpp

#include<bits/stdc++.h>
using namespace std;

void AddFive(int &num) {
    cout << "num" << endl;
    num += 5;
    cout << "num" << endl;
    num += 5;
    cout << "num" << endl;
}

int main() {
    int num;
    cin >> num;
    AddFive(num);
    cout << num;
    return 0;
}

Input: 10
Output: 15
20
20