C++18: Function Examples

Design a function square() which will calculate and return the square of the number which is passed as arguments

#include <iostream>
using namespace std;
//Value returning Function
int square(int n){
    int sq = n*n;
    return(sq);
}
//Value not returning Function
void squ(int n){
    int sq = n*n;
    cout<<"Square of "<<n<< " is "<<sq<<endl;
}
main()
{
    int x =square(5);
    cout<<"Square is "<<x<<endl;
    int z = 2*square(10);
    cout<<"z = "<<z<<endl;
    squ(5);
    squ(10);
}

Output:

Square is 25
z = 200
Square of 5 is 25
Square of 10 is 100

2. Design a two function volume and perimeter which() will calculate and print the result when L, B, H of rectangle are passes as arguments.

#include <iostream>
using namespace std;
main()
{
  

void volume(int l,int b,int h){
    int vol = l*b*h;
    cout<<"Volume is "<<vol<<endl;
}
void surfacearea(int l,int b,int h){
    int sur = 2*(l*b + l*h + h*b);
    cout<<"Surcace area is "<<sur<<endl;
}
int main()
{
    int l,b,h;
    cout<<"Enter Length , Breadth And Height of Rectangle: "<<endl;
    cin>>l>>b>>h;
    volume(l,b,h);
    surfacearea(l,b,h);
    return 0;
}

Output:

Enter Length , Breadth And Height of Rectangle:
20 10 30
Volume is 6000
Surcace area is 2200

WAP to find the area and circumference of a circle. 

#include <iostream>
using namespace std;
void area(int r){
    float a = 3.14*r*r;
    cout<<"Area of Circle is "<<a<<endl;
}
void circumference(int r){
    float c = 2*3.14*r;
    cout<<"Circumference of circle is "<<c<<endl;
}
main(){
    int r;
    cout<<"Enter radius of circle: "<<endl;
    cin>>r;
    area(r);
    circumference(r);
}

Output:

Enter radius of circle:
20
Area of Circle is 1256
Circumference of circle is 125.6

WAP to find area and perimeter of rectangle using void functions.

#include <iostream>
using namespace std;
void area(int l, int b)
{
    int ar = l * b;
    cout << "Area of circle is " << ar << endl;
}
void perimeter(int l, int b)
{
    int p = 2 * (l + b);
    cout << "Perimeter of Rectangle is " << p << endl;
}
int main()
{
    int l, b;
    cout << "Enter length and breadth of Rectangle: " << endl;
    cin >> l >> b;
    area(l, b);
    perimeter(l, b);
    return 0;
}

Output:

Enter length and breadth of Rectangle:         
5 10
Area of circle is 50
Perimeter of Rectangle is 30

Value returning Functions:

WAP to find volume and surface area of cuboid using value returning functions.

#include <iostream>
using namespace std;
int volume(int l,int b,int h){
    int vol = l*b*h;
    return(vol);
}
int surfacearea(int l,int b,int h){
    int sur = 2*(l*b + l*h + h*b);
    return(sur);
}

int main()
{
    int l,b,h;
    int v,s;
    cout<<"Enter the length, breadth and height of cuboid: "<<endl;
    cin>>l>>b>>h;
    v=volume(l,b,h);
    cout<<"Volume is "<<v<<endl;
    s=surfacearea(l,b,h);
    cout<<"Surface area is "<<s<<endl;
    return 0;
}

Output:

Enter the length, breadth and height of cuboid:
34 23 34
Volume is 26588
Surface area is 5440

WAP to find out area and perimeter of a rectangle using value returning functions.

#include <iostream>
using namespace std;
int area(int l,int b){
    int ar = l*b;
    return(ar);
}
int perimeter(int l,int b){
    int p = 2*(l+b);
    return(p);
}
int main()
{
    int l,b;
    int a,p;
    cout<<"Enter the length and breadth of rectangle: ";
    cin>>l>>b;
    a=area(l,b);
    cout<<"The area of rectangle is "<<a<<endl;    
    p= perimeter(l,b);
    cout<<"The perimeter of rectangle is "<<p<<endl;
    return 0;
}

Output:

Enter the length and breadth of rectangle: 5 8
The area of rectangle is 40
The perimeter of rectangle is 26

WAP to find out factorial using value returning functions.

#include <iostream>
using namespace std;
int fact(int n){
    int fact,temp;
    for (int i = 0; i < n; i++)
    {
        temp = i*n;
        fact += temp;
    }
    return(fact);
}
int main()
{
    int n,f;
    cout<<"Enter a Number : ";
    cin>>n;
    f=fact(4);
    cout<<"Factorial of "<<n<<" is "<<f<<endl;
    
    return 0;
}

Output:

Enter a Number : 5
Factorial of 5 is 50

WAP to create sum function returning sum of three num and mean function returning mean of the three digit.

#include <iostream>
using namespace std;
int sum(int a,int b,int c){
    
    return(a+b+c);
    cout<<a+b+c;
}
float mean(int p,int q,int r){
    float m=sum(p,q,r)/3;
    return(m);
} 
int main()
{
    int a,b,c;
    int sm , me;
    cout<<"Enter three numbers: ";
    cin>>a>>b>>c;
    sm = sum(a,b,c);
    cout<<"Sum of entered numbers is : "<<sm<<endl;
    me = mean(a,b,c);
    cout<<"Mean of entered numbers is: "<<me<<endl;


    return 0;
}

Output:

Enter three numbers: 5 8 12
Sum of entered numbers is : 25
Mean of entered numbers is: 8

WAP to create two functions is_Even and is_false returning bool as per condtion.

#include <iostream>
using namespace std;
int is_Even(int n)
{
    if (n % 2 == 0)
        return true;
    else
        return false;
}
int is_Odd(int n)
{
    if (!n % 2 == 0)
        return true;
    else
        return false;
}
int main()
{
    int n;
    cout << "Enter a number :";
    cin >> n;
   cout << "is Even: " << is_Even(n) << endl;
    cout << "is Odd : " << is_Odd(n) << endl;
    return 0;
}

Output:

Enter a number :5
is Even: 0
is Odd : 1

Comment  if you have any questions!