C二维数组用指针地址遍历

Posted 2020-10-27 王默

#include <stdio.h>
#include <stdlib.h>
int main(){
	int a = 100;
	void *p = &a;
	printf("a:%d address:%p\n",*(int*)p, &a);
	//unsigned int *pt = (unsigned int*)0xbfa70ee8;
	int *pt = (int*)malloc(sizeof(int));
	*pt = 200;
	printf("ptv:%p v:%d\n",pt,*pt);
	
	printf("********************行指针遍历二维数组*************************\n");

	//二维数组的指针地址
	int fa[3][4] = {{1,2,3,4},{5,6,7,8},{9,10,11,12}};
	//行指针指针遍历输出二维数组
	int i,j;
	for(i=0;i<3;i++)
	{
		for(j=0;j<4;j++){
			printf("fa[%d][%d]=%d %p\n",i,j, *(*(fa+i)+j),*(fa+i)+j);
		}
	}
	printf("******************用数组名 列指针遍历二维数组***************************\n");
	//定义指针
	int *col = fa[0];//col是某行某列的指针 把第一行地址赋值给指针col
	for(;col<fa[0]+12; col++){
		//地址每次循环+1指向下一行一列
		if( (col-fa[0])%4==0 ){
			printf("\n");	
		}	
		printf("%d ", *col);
	}
	printf("******************用指针 列指针遍历二维数组***************************\n");
	int *pp = *fa;
	int *arr = *fa;//二维数组首地址等同于 int *arr = fa[0]
	for(;arr<pp+12; arr++){
		//地址每次循环+1指向下一行一列
		if( (arr-pp)%4 == 0 ){
			printf("\n");	
		}	
		printf("%d ", *arr);
	}

	
	return 0;
	
}