passptr.c

来自「c21Examples.rar」· C语言 代码 · 共 58 行

/* Passing a pointer to a function as an argument. */

#include <stdio.h>

/* The function prototypes. The function func1() takes as */
/* its one argument a pointer to a function that takes no */
/* arguments and has no return value. */

void func1(void (*p)(void));
void one(void);
void two(void);
void other(void);

int main( void )
{
    /* The pointer to a function. */
    void (*ptr)(void);
    int nbr;

    for (;;)
    {
        puts("\nEnter an integer between 1 and 10, 0 to exit: ");
        scanf("%d", &nbr);

        if (nbr == 0)
            break;
        else if (nbr == 1)
            ptr = one;
        else if (nbr == 2)
            ptr = two;
        else
            ptr = other;
        func1(ptr);
    }
    return 0;
}

void func1(void (*p)(void))
{
    p();
}

void one(void)
{
    puts("You entered 1.");
}

void two(void)
{
    puts("You entered 2.");
}

void other(void)
{
    puts("You entered something other than 1 or 2.");
}