C语言函数指针命令行参数

我们可以用函数指针实现多态等高端函数，再加上命令行参数让你的程序提高一个档次。

程序如下：

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<assert.h>int f1(int a){printf("f1:%d\n",a);return a;}int f2(int a){printf("f2:%d\n",a);return a*a;}int f3(int a){printf("f3:%d\n",a);return a*a*a;}int main(int argc, char*argv[]){int (*m)(int);int iflag = 1;int a = 2;if (argc > 1) iflag = atoi(argv[1]);if (argc > 2)a = atoi(argv[2]);switch(iflag){case 1:m = &f1;break;case 2:m = &f2;break;case 3:m = &f3;break;default:break;}printf("%d\n",m(a));return 0;}

编译与运行：

-bash-4.1$ gcc -o a Demo.c-bash-4.1$ ./af1:22-bash-4.1$ ./a 2f2:24-bash-4.1$ ./a 3f3:28-bash-4.1$ ./a 3 4f3:464-bash-4.1$ ./a 3 5f3:5125-bash-4.1$ ./a 3 6f3:6216-bash-4.1$ ./a 2 6f2:636-bash-4.1$ ./a 1 6f1:66-bash-4.1$