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);  

Answer 1

I think the first solution is best.

char myArray[MAX] = {0};  //best of all

Answer 2

Either can be used

But I feel the below more understandable and readable ..

  char myArray[MAX]; 
  memset(myArray, 0, MAX);

Answer 3

Assuming that you always want to initialize with 0.

--> Your first way and 2nd way are same. I prefer 1st.

--> Third way of memset() should be used when you want to assign 0s other than initialization.

--> If this array is expected to initialized only once, then you can put static keyword ahead of it, so that compiler will do the job for you (no runtime overhead)

Answer 4

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 5

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.

Answer 6

You can use also bzero fn (write zero-valued bytes)

#include <strings.h>
void bzero(void *s, size_t n)

http://linux.die.net/man/3/bzero