This MATLAB function, named `threeSevens`, checks whether an input array,...

This MATLAB function, named threeSevens, checks whether an input array, x, contains exactly three occurrences of the number 7. Here's a step-by-step breakdown of what the code does:

1. count = sum(x == 7);: This line checks each element of the input array x to see if it equals 7. The result is a logical array where true represents each instance of 7. sum then adds up the number of true values to calculate how many times 7 appears in the array.

2. if count == 3: This checks whether the count of 7s is exactly three.

3. If the count is exactly three, b = true is assigned, meaning the function returns true.

4. If the count is not three, b = false is assigned, meaning the function returns false.

In summary, the function returns true if the input array contains exactly three 7s, and false otherwise.