Meaning of complex C syntax [duplicate]

Answer 1

c is an array of 10 function pointers that return a char* and take a int** as an argument.

(*c[10])
   ^^^^ = array of 10

(*c[10])
 ^ = function pointer

So right now we have an array of 10 function pointers.

char *(*c[10])
^^^^^^ = returns a char*

char *(*c[10])(int** p)
               ^^^^^ = takes a int** as an argument

Array of 10 function pointers that return a char* and take a int** as an argument.

_{NOTE: If you write code like this you deserve to be slapped in the face.}

Answer 2

Type declaration involves three operators: array [SIZE], pointer * and function (type1 param1, type2 param2, ...). Remember that all the three operators are right-associative.

char *(*c[10])(int **p);

Let's add more parenthesis to make the associativity more clear.

char *((*(c[10]))(int *(*p)))

Start from c, the variable.

c[10] means "c is an array of 10 elements, but each element is a ..."

Then see the * beside it. *(c[10]) means "c is an array of 10 elements, each element is a pointer pointing to ..."

Then (*(c[10]))(int *(*p)) means "c is an array of 10 elements, each element is a pointer to a function, which returns ..." Using similar methods we see the function takes one parameter which is "a pointer to a pointer to an int".

Then *((*(c[10]))(int *(*p))) means "c is an array of 10 elements, each element is a pointer to a function, which returns a pointer to a ..."

Finally char *((*(c[10]))(int *(*p))) means "c is an array of 10 elements, each element is a pointer to a function, which returns a pointer to a char". That's it.

I find the Clockwise/Spiral Rule very useful. See http://c-faq.com/decl/spiral.anderson.html

But I'd rather add more brackets than using spirals.