Return value type (* pointer variable name) ([parameter list]);
1、int func(int x)； /* Declare function */
2、int(* f)(int x)； /* Declare a function pointer */
3. f = func/* Assign the first address of the func function to the pointer f */
Second, the usage of function pointer:
Application of function pointer: (* pointer variable name) (parameter list)
Such as int c=(*ptr)(a, b); /* Use of function pointers */
In C language, the function itself is not a variable, but you can define a pointer to the function, also called a function pointer, which points to the entry address of the function. This type of pointer can be assigned, stored in an array, passed to a function, returned as a function, and so on. ?
Extended data:
The difference between pointer function and function pointer:
1, both of which are abbreviations. Pointer function refers to a function whose return value is a pointer, that is, it is essentially a function. We know that all functions have a return type (no return value is no value), but the return type of pointer function is some kind of pointer.
2. The function of returning a pointer is widely used. In fact, each function has its own entry address, which is equivalent to a pointer, even if it does not return a pointer of a certain type. For example, if a function returns an integer value, it is actually equivalent to returning the value of a pointer variable, but the variable at this time is only the function itself, and the whole function is equivalent to a "variable".
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