Functions
Functions can't return arrays, and it's tricky to write a function as if it returns an array (perhaps by simulating the array with a pointer) because you have to be careful about allocating the memory that the returned pointer points to.The functions we've written have all accepted a well-defined, fixed number of arguments. printf accepts a variable number of arguments (depending on how many %signs there are in the format string) but we haven't seen how to declare and write functions that do this.
