Difference between 0, \ 0, and null

I know where to use it, but the truth is unclear. Then google, a better explanation, although in English, is very classic.

1.0 is an integer constant

2.'\ 0' is a character constant

3.Null is a macro (macro)
Defined in several standard headers (standard header file)

4.Nul is the name of the character constant .. I have never seen it anyway =)

All of these are ** not * interchangeable (not interchangeable)


Their usage is as follows:
1.0 can be used anywhere, it is the generic symbol for each type's zero value and the compiler will sort things out.

2.'\ 0' shoshould be used only in a character context.

3.Null is to be used for pointers only since it may be defined as (void *) 0), this wowould cause problems with anything
But pointers.

4.Nul is not defined in C or C ++, it shouldn't be used unless you define it yourself in a suitable manner, like:# Define
Nul '\ 0'