What is the difference between the two declarations in c?

Question

typedef int F1(int x);

int F1(int x);

The same for me, either with help typedefor not.

Answer 1

typedefdoes not declare a variable; he declares a type.

After you say:

typedef int F1(int x);

further in your code you can do this:

F1 myfunction;

which is equivalent to:

int myfunction(int x);

Answer 2

typedef int F1(int x);

You define the type of function F1, which is a function that takes an integer as an argument and returns an integer

int F1(int x);

You define a function called F1