Depends on the compiler, and on compiler options: some do always clear arrays when they are created, some don't - and in the later case it won't.
Technically, it's part of the C standard that this code:
type name[size] = {};
will produce an initialized array - but not all compilers are 100% compliant.
If you are concerned about portability, you should probably explicitly use
C library function - memset() - Tutorialspoint[
^] to preset your array before you use it.