C - 指针与数据

/*day_mon.c -- 打印每月的天数*/
#include <stdio.h>
#define MONTHS 12
#define MAX_LEN 80

int main(void)
{
　　/*使用const表示char为只读数据，不允许被修改*/    
　　const char months[MONTHS][MAX_LEN] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "Nobember", "December"};
    int days[MONTHS] = {31, 28, 31, 30, 31, 30, 31, 31, 30 ,31, 30, 31};
    int index, year;
    
    /*程序输入年份*/
    puts("Enter year: ");
    scanf("%d", &year);
    
    /*闰年二月29天，平年28天*/
    if( (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0) )
        days[1] = 29;
    
    /*程序打印输出*/
    puts("Month            Day");
    for(index=0; index<MONTHS; index++)
        printf("%s            %d\n", months[index], days[index]);
    
    return 0;
}

int arr[6] = {[5] = 212};　　//把arr[5]初始化

/*rain.c -- 针对若干年的降水量，计算年隆水总量、年降水平均量，以及月降水平均量*/
#include <stdio.h>
#define MONTHS 12        //一年的月份数
#define YEARS 5            //降水量数据的年数

int main(void)
{
    /*把数组初始化为2010年到2014年降水量数据*/
  const float rain[YEARS][MONTHS]={
    {4.3,4.3,4.3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6},
    {8.5,8.2,1.2,1.6,2.4,0.0,5.2,0.9,0.3,0.9,1.4,7.3},
    {9.1,8.5,6.7,4.3,2.1,0.8,0.2,0.2,1.1,2.3,3.6,8.4},
    {7.2,9.9,8.4,3.3,1.2,0.8,0.4,0.9,0.6,1.7,4.3,6.2},
    {7.5,5.6,3.8,2.8,3.8,0.2,0.0,0.0,0.0,1.3,2.6,5.2}
  };

  int year,month;
  float subtot, total;

  printf(" YEAR RAINFALL (inches) \n");
  for(year = 0, total = 0; year < YEARS; year++)
  {
    for(month = 0,subtot = 0; month < MONTHS; month++)
    {
      subtot += rain[year][month]; 
    }
    printf("%5d %15.1f\n", 2010+year, subtot);
    total += subtot;
  }

  printf("\nThe yearly average is %.1f inches. \n\n ", total/YEARS);
  printf("MONTHLY AVERAGES: \n\n");
  printf("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec\n");
  
  for(month = 0; month < MONTHS; month++)
  {
    for(year=0,subtot=0; year<YEARS;year++)
    subtot += rain[year][month];
    printf("%4.1f", subtot/YEARS);
  }
 
  printf("\n");
  return 0; 
}

int a[100];

a == &a[0]  //数组名同时也是该数组首元素的地址。