FUNCTION.CPP

// This program converts a binary number to a decimal number using a function.

#include<iostream>
using namespace std;
/*void BinToDec(int BinNo){                                                    //function definition
    int n = BinNo; int DecNo = 0; int pow=1;
    while(n>0){
        int LastDigit = n%10;                                                 //to get the last digit of the binary number
        DecNo = DecNo + LastDigit*pow;                                    //to add the value of the last digit to the decimal number
        pow = pow*2;                                                        //to calculate the power of 2 for the next digit            
        n = n/10;                                                              //to remove the last digit of the binary number
    }
    cout << "The decimal no is: " << DecNo << endl;
}
int main(){
    int BinNo;
    cout << "Enter a binary number: ";
    cin >> BinNo;
    BinToDec(BinNo);                                                          //function call
    return 0;
}



// This program converts a binary number to a decimal number using a function.

void BinToDec(int DecNo){
    int n = DecNo; int BinNo = 0; int pow = 1;
    while(n>0){
        int rem = n%2;
        BinNo = BinNo + rem*pow;
        pow = pow*10;
        n = n/2;                                                                 
    }
    cout << "The binary equivalent is: " << BinNo << endl;
}int main(){
    int DecNo;
    cout << "Enter a decimal number: ";
    cin >> DecNo;
    BinToDec(DecNo);                                                          //function call
    return 0;
}



// adding two numbers using a function

int sum(int a,int b){                                                            //a and b are parameters                                           
    return a+b;}                                                       //parameters are variables jiske andar koi bhi value store ho sakti h 
    int main(){
        cout<<sum(4,9)<<endl;                                                    //4,9 are arguments(are fixed value)
        return 0;                                                    
    } 



// to print if a no. is even or odd using a function

void EvenOdd(int n){
    if(n%2==0){
        cout << n << " is an even number." << endl;
    }
    else{
        cout << n << " is an odd number." << endl;
    }}int main(){
    int n; cout<<"enter a no. :"; cin>>n;
    EvenOdd(n);
    return 0;}


// to calculate the factorial of a no. using a function
void func(){
    int factorial=1; int n; cout<<"enter a no. :"; cin>>n;
    for(int i=1;i<=n;i++){
        factorial = factorial*i;
    }
    cout << "The factorial of " << n << " is: " << factorial << endl;
}int main(){
    func();
    return 0;}  


// check no is prime or not using a function
void func(){
    int n; bool isPrime = true; cout<<"enter a no. :"; cin>>n;
    for(int i=2;i<=n-1;i++){
        if(n%i==0){
            isPrime = false;
            break;
        }
    }
    if(isPrime){
        cout << n << " is a prime number." << endl;
    }
    else{
        cout << n << " is not a prime number." << endl;
    }}int main(){
    func();
    return 0;}    */