What are bit fields?

The arguments which we pass to the main() function while executing the program are called as command line arguments. The parameters are always strings held in the second argument (below in args) of the function which is array of character pointers. First argument represents the count of arguments (below in count) and updated automatically by operating system.

It compares two strings by ignoring the case.

Opens a file both for reading and writing. If a file is not existing it creates one, else if the file is existing it will be over written.

It cannot be used on constants. It cannot be used on variable which are declared using register storage class.

No, it is a structure defined in stdio.h.

Error, It is invalid that either of the operands for the modulus operator (%) is a real number.

There is only one operator and is conditional operator (? : ).

goto

A pointer holding the reference of the function is called pointer to a function. In general it is declared as follows.

T (*fun_ptr) (T1,T2…); Where T is any date type.

Once fun_ptr refers a function the same can be invoked using the pointer as follows.

fun_ptr();
[Or]
(*fun_ptr)();