The difference between int *p () and int (*p) ()

int *p () is a function that returns a pointer

Int (*p) () is a pointer to a function

function that returns the pointer:

int * A (int x,int y);

There are a number of students (each student has 4 courses), requiring the user to enter the student serial number, can output the student's full results. Implemented with pointer functions.

#include

void main()

{float *score[ ] [4]={{60,

                     {56 , Span style= "font-family: ' Times New Roman ';" >89 , 67 , 88} , {34 , 78 , , 66}};

float ? *search(float (*pointer)[4],int n);

float? *p;

int i,m;

printf(″Enterthe number of student: ″);

scanf(″%D″,&M);

printf(″ thescores of No. %d is:\n″,m);

p=Search(score,m);

　for (i=0;i<4;i++ )

　printf(″%5. 2f\t″,*(p+i));

｝

Float * Search (float (*pointer) [4 ],int N)

{ float *pt;

pt=*(pointer+n);/ /(equivalent to *(* (p+n) +0))=* (* (p+n) )

return (PT);

}

For the students in the example above, find out which students have failed courses and their student numbers.

#include

void main()

{float *score [  ][4 ] ={{60 , 70 , 80 , , style= "font-family: ' Times New Roman ';" >{56 ,

---------------------;

Float Search(float (*pointer)[4]);

float? *p;

Int i,j;

for (i=0;i<3;i++)

{p=search(score +i);

if (p==*(score+i))

{printf(″no. %d scores: ″,i);

for (j=0;j<4;j++)　

　　printf(″%5.2F″,*(p+j));

printf(″\n″);}　

　　 }

}

Pointers to functions

argument function name F1 f2　

　 ↓ ↓　　

void Sub (int (*x1) (int) ,Int (*x2) (int,int) )

{ int a,b,i,j;

a=(*x1)(i); /* call F1 function */

b=(*x2)(i,j);/* call f2 function */

...

}

Example: Set up a function processthat implements different functions each time it is called. Enter A and b two numbers, first call the process to find A and B in the large, the second to find the small one, the third to seek the sum of A and B.

#include

void main()

{ int max(int,int); /* function Declaration * /

int min(int,int); /* function Declaration * /

int add(int,int);/ * function Declaration * /

void process (int, int, int (*fun) (); /* function Declaration * /

　 int A, b;

　printf(″Enter a and b: ″);

　scanf(″%D,%D″,&A,&B);

printf(″max=″);

Process (A,b,max);

　printf(″min=″);

　process(a,b,min);

　printf(″sum=″);

　process(A,b,add);

｝

......

int Add (int x,int y) / * function definition * /

{ intz;

z=x+y;

return(z);

｝

void process (int x,int y,Int (*fun) (int,int))

{ int result;

result = (*fun) (x, y);

printf(″%d\n″, result);

｝

The difference between int *p () and int (*p) ()