# Erle Robotics C++ GitBook

## Simple examples

For now you know how to calculate 3^4 using for loop, like this example:

#include <iostream>
using namespace std;

int main() {
int threeExpFour = 1;

for (int i = 0; i < 4; i = i + 1){
threeExpFour = threeExpFour * 3;
}
cout << "3^4 is " << threeExpFour << endl;
return 0;
}


This example shows the result of 3^4. Now we want to do the same but using functions.That is, define the function threeExpFour which calculates the value of 3^4.This is very simple if we use a built-in function: pow(base,exp) from the cmath library.

#include <iostream>
#include <cmath>
using namespace std;

int main() {
int threeExpFour = pow(3, 4);
cout << "3^4 is " << threeExpFour << endl;

return 0;
}


In the cmathmodule you can find many others mathematical functions. Here you will find a list.

This link leads you to the official web site library. Here you can find all the built-in functions.

Finally, here is another list of built-in functions, with use examples for each of them.