Reset C int array to zero : the fastest way?

Question

Assuming that we have a T myarray[100] with T = int, unsigned int, long long int or unsigned long long int, what is the fastest way to reset all its content to

Answer 1

From memset():

memset(myarray, 0, sizeof(myarray));

You can use sizeof(myarray) if the size of myarray is known at compile-time. Otherwise, if you are using a dynamically-sized array, such as obtained via malloc or new, you will need to keep track of the length.