6、编程基础与Objective - C入门全解析

编程基础与Objective - C入门全解析

1. 时间处理挑战

在编程中，处理时间是常见需求。标准C库使用 struct tm 来存储分解后的时间信息，其定义如下：

struct tm {
    int    tm_sec;     /* seconds after the minute [0 - 60] */
    int    tm_min;     /* minutes after the hour [0 - 59] */
    int    tm_hour;    /* hours since midnight [0 - 23] */
    int    tm_mday;    /* day of the month [1 - 31] */
    int    tm_mon;     /* months since January [0 - 11] */
    int    tm_year;    /* years since 1900 */
    int    tm_wday;    /* days since Sunday [0 - 6] */
    int    tm_yday;    /* days since January 1 [0 - 365] */
    int    tm_isdst;   /* Daylight Savings Time flag */
    long   tm_gmtoff;  /* offset from CUT in seconds */
    char   *tm_zone;   /* timezone abbreviation */
};