[C][代码实例]交换指向常量的二级指针的位置

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#define ARR_LEN 3
#define STR_LEN 3

void swap(const char**, const char**);

int main( void )
{
char str_1[ARR_LEN][STR_LEN] = {
		"ap\0",
		"br\0",
		"dr\0"
	};

	const char **Pstr_1 = malloc( sizeof( char* ) * 3 );
	int i = 0;

	for (; i < ARR_LEN; ++i)
	{
		//*( Pstr_1 + i ) = malloc( sizeof( char ) * 3 );//你可以给指针分配自己的空间
		*( Pstr_1 + i ) = *( str_1 + i );//但是现在我们先复制str_1的指针给它们
	}

i = 0;
	for (; i < ARR_LEN; ++i)
	{
		printf( "%s\n", *( Pstr_1 + i ) );
	}

	swap((Pstr_1 + 0), (Pstr_1 + 1));

	i = 0;
	for (; i < ARR_LEN; ++i)
	{
		printf( "%s\n", *( Pstr_1 + i ) );
	}

return 0;

}

void swap(const char **p1, const char **p2)
{
	const char *pTemp = *p1;
	*p1 = *p2;
	*p2 = pTemp;
}