C Language Study-function pointer usage

C Language Study-function pointer usage
Function pointer usage

 

1. function pointer Definition

The first time I used the function pointer, I declared it like this,Typedef void (* pSimulatepks) (uint8 * prxBuf, uint8 * prxBufLen );

The first bracket () is used to package pSimulatepks into a pointer, and the second bracket () is a function parameter list. Therefore, pSimulatepks is a function pointer, pointer to such a type of function.

A function pointer is declared above, so that a function pointer can be defined in this way,PSimulatepks pfun;

 

2. function pointer call Function

 

For example, a function isVoid fun (uint8 * prxBuf, uint8 * prxBufLen );You can do this,Pfun = fun;

You can call fun later,Pfun (rxBuf, & rxBufLen );Or(* Pfun) (rxBuf, & rxBufLen );

3. function pointer as function return value

PSimulate simFunc (uint8 cmd)

{

Switch (cmd)

{

Case 0x01:

Return sim_a;

 

Case 0x02:

Return sim_ B;

Case 0x03:

Return sim_c;

Case 0x04:

Return sim_d;

}

}

Among them, sim_a sim_ B sim_c sim_d is the function name of this class function.