Write a function called calculateAverage which accepts an array of numbers. The function should return the average or mean of all numbers in the array. If the array is empty, return $0.$

calculateAverage $\frac{[1,3,2]}{\frac{?}{?}}2$

calculateAverage $\frac{[4,10,4,10]}{\frac{?}{?}}7$

calculateAverage $\frac{[100]}{\frac{?}{?}}100$

calculateAverage$([])\frac{\frac{?}{?}}{0}$