C ++ obtains the current system time

C ++ obtains the current system time

# Include

// * Method 1

Time_t tt = time (NULL); // The returned result is only a time (cuo ).

Tm * t = localtime (& tt );

Printf ("% d-% 02d-% 02d % 02d: % 02d: % 02dn ",

T-> maid + 1900,

T-> tm_mon + 1,

T-> tm_mday,

T-> tm_hour,

T-> tm_min,

T-> tm_sec );

// * Method 2

SYSTEMTIME st = {0 };

GetLocalTime (& st );

Printf ("% d-% 02d-% 02d % 02d: % 02d: % 02dn ",

St. wYear,

St. wMonth,

St. wDay,

St. wHour,

St. wMinute,

St. wSecond );

Below a few, is online to find: Reprint address: http://apps.hi.baidu.com/share/detail/17815869

I personally think the second one is more practical and most commonly used ~

However, do not forget second when computing algorithms are time-consuming. You can't just use Milliseconds to reduce them without negative values. If the algorithm is time-consuming, you must use minutes. Otherwise, hours ......

// Solution-advantage: only the C standard library is used; disadvantage: only seconds are allowed

# Include

# Include

Int main (void)

{

Time_t t = time (0 );

Char tmp [64];

Strftime (tmp, sizeof (tmp), "% Y/% m/% d % X % A % j day % z this year", localtime (& t ));

Puts (tmp );

Return 0;

}

Size_t strftime (char * strDest, size_t maxsize, const char * format, const struct tm * timeptr );

Generate a string based on the format string.

Struct tm * localtime (const time_t * timer );

Obtain the local time. the result obtained by localtime is returned by the structure tm.

The returned string can be in the following format:

% A abbreviation of the day of the week. Eg: Tue

% A full name of the day of the week. Eg: Tuesday

The abbreviation of % B month name.

% B full name of the month name.

% C the local date time is better than the string.

% D indicates the day of the month (range: 00 to 31) with a number ). Date

% H indicates the hour in the 24-hour format (ranging from 00 to 23 ).

% I represents the hour in 12-hour format (range: 01 to 12 ).

% J indicates the day of the year (range: 001 to 366 ).

The number of % m months (ranging from 1 to 12 ).

% M minutes.

% P uses ''am'' or ''pm ''to indicate the local time.

% S seconds.

% U indicates the week of the current year. The first week starts from the first Sunday.

% W indicates the week of the current year. The first week starts from the first Monday.

% W indicates the day of the week by number (0 indicates Sunday ).

% X date representation without time.

% X does not include the time representation of the date. Eg: 15:26:30

The two digits % y indicate the year (range: 00 to 99 ).

% Y indicates the complete year number, that is, the four-digit number. Example: 2008

% Z (% z) Time Zone or abbreviation. Eg: China Standard Time

% Characters.

// Solution 2 advantages: accurate to milliseconds; disadvantage: windows API is used

# Include

# Include

Int main (void)

{

SYSTEMTIME sys;

GetLocalTime (& sys );

Printf ("% 4d/% 02d/% 02d % 02d: % 02d: % 02d. % 03d week % 1dn ", sys. wYear, sys. wMonth, sys. wDay, sys. wHour, sys. wMinute, sys. wSecond, sys. wMilliseconds, sys. wDayOfWeek );

Return 0;

}

// Solution 3. Advantages: using system functions, you can modify the system time.

// This file must be a c ++ File

# Include

# Include

Using namespace std;

Void main ()

{

System ("time ");

}

// Solution 4: Convert the current time to seconds, and then use the corresponding time to convert

// This file must be a c ++ File

# Include

# Include

Using namespace std;

Int main ()

{

Time_t now_time;

Now_time = time (NULL );

Cout <

Return 0;

}

Note: GetLocalTime () and GetSystemTime () are different.