 # C++ Programming Code Examples

## C++ > Mathematics Code Examples

### calculator program in c++ using functions

``` calculator program in c++ using functions Write a program for a simple c++ calculator which have different functions for different operations. Make a menu base selection screen using switch statement. Ever operation should have its own function. This code may also be use as a mini project to start. Calculator should have following operations. Addition Subtraction Multiplication Division Square root Factorial Exponential #include<iostream> #include<conio.h> #include<math.h> #include<stdlib.h> #include<iomanip> char op; using namespace std; void sum() { int sum = 0; int n; int numberitems; cout << "Enter number of items: \n"; cin >> numberitems; for(int i=0;i<numberitems;i++) { cout<< "Enter number "<<i<<":\n\n" ; cin>>n; sum+=n; } cout<<"sum is: "<< sum<<endl<<endl; } void diff() { int diff; int n1,n2; cout<<"enter two numbers to find their difference:\n\n"; cout<<"enter first number:"; cin>>n1; cout<<"\nenter second number:"; cin>>n2; diff=n1-n2; cout<<"\ndifference is:"<<diff<<endl<<endl; } void pro() { int pro=1; int n; int numberitems; cout<<"enter number of items:\n"; cin>>numberitems; for(int i=0;i<=numberitems;i++) { cout<<"\nenter item "<<i<<":"; cin>>n; pro*=n; } cout<<"product is:"<<pro<<endl<<endl; } void div() { int div; int n1; int n2; cout<<"enter 2 numbers to find their quotient\n\n"; cout<<"enter numerator:"; cin>>n1; cout<<"\nenter denominator:"; cin>>n2; div=n1/n2; cout<<"\nquotient is:"<<div<<endl<<endl; } void power() { long int p; int res=1,n; cout<<"enter number:"; cin>>n; cout<<"\nenter power:"; cin>>p; for(int i=1;i<=p;i++) { res=n*res; } cout<<n<<"\n power "<<p<<" is :"<<res<<endl; } void sq() { float s; int n; cout<<"enter number to find its square root:"; cin>>n; s=sqrt(n); cout<<"\nsquare root of "<<n<<" is :"<<s<<endl; } void fact() { long int f=1; int c=1,n; cout<<"enter number to find its factorial:"; cin>>n; while(c<=n) { f=f*c; c+=1; } cout<<"\nfactorial of "<<n<<" is :"<<f<<endl; } void expo() { long double res=1,p; double e=2.718281828; cout<<"enter power of exponential function:"; cin>>p; for(int i=1;i<=p;i++) { res=e*res; } cout<<" e^ "<<p<<" is :"<<res<<endl; } int main() { system("cls"); do { system("pause"); system("cls"); cout<<"which operation you want to perform\n"; cout<<"press 0 for exit\n"; cout<<"press 1 for addition \n"; cout<<"press 2 for subtraction\n"; cout<<"press 3 for multiplication\n"; cout<<"press 4 for division\n"; cout<<"press 5 for power calculation\n"; cout<<"press 6 for square root \n"; cout<<"press 7 for factorial calculation\n"; cout<<"press 8 for exponential calculation\n"; cout<<"press option:"; cin>>op; switch(op) { case '1': sum(); break; case '2': diff(); break; case '3': pro(); break; case '4': div(); break; case '5': power(); break; case '6': sq(); break; case '7': fact(); break; case '8': expo(); break; case '0': exit(0); default: cout<<"invalid input" ; system("cls"); } } while(op!='0'); getch(); } ``` 