>The output of the above program will be “NULL is 0”, so it is quite evident that NULL is defined as “0” in C language.
To be pedantic, all that's evident from the observed behaviour is that in C, NULL compares equal to the integer literal 0. The expressions may be, and usually are not mutually interchangeable both ways, as they (may) have different types.
To be pedantic, all that's evident from the observed behaviour is that in C, NULL compares equal to the integer literal 0. The expressions may be, and usually are not mutually interchangeable both ways, as they (may) have different types.