Array initialization with {0}, {0,}?

Question

Say I want to initialize myArray

char myArray[MAX] = {0};   char myArray[MAX] = {0,};   char myArray[MAX]; memset(myArray, 0, MAX);   

Are they all equal or any preferred over another?

Thank you

Answer 1

Actually, in C++, I personally recommend:

char myArray[MAX] = {}; 

They all do the same thing, but I like this one better in C++; it's the most succinct. (Unfortunately this isn't valid in C.)

By the way, do note that char myArray[MAX] = {1}; does not initialize all values to 1! It only initializes the first value to 1, and the rest to zero. Because of this, I recommend you don't write char myArray[MAX] = {0}; as it's a little bit misleading for some people, even though it works correctly.

Answer 2

They are equivalent regarding the generated code (at least in optimised builds) because when an array is initialised with {0} syntax, all values that are not explicitly specified are implicitly initialised with 0, and the compiler will know enough to insert a call to memset.

The only difference is thus stylistic. The choice will depend on the coding standard you use, or your personal preferences.