Objective-C Programming Summary (article 4) date type operations

Obtain the current date: nsdate * Date = [nsdate date]; // However, In this method, the UTC event is obtained.

Nsdate * Date = [nscalendardate date]; // obtain the local time.

Get the date of yesterday:

Nsdate * Yesterday = [[nscalendardate date] datebyaddinginternalinterval:-24*60*60];

Get the specified time:

Nsdate * nationaldate = [nsdate datewithstring: "00:00:00 + 0800"];

There is also a time string creation time object in the specified format:

Nsdateformatter * formatter = [[nsdateformatter alloc] init];

[Dateformatter setdateformat: @ "yyyy-mm-dd hh: mm: SS"];

[Dateformatter settimezone: @ "H"]; // H indicates + 0800. The corresponding I indicates + 0900. Z indicates-0100.

Nsdate * nationaldate2 = [formatter datefromstring: @ "00:00:00"];

The third method to use the string creation time is:

Nsdate * Date = [nscalendardate datewithstring: @ "4 Mar 2012" calendarformat: @ "% d % B % Y"]; // SPECIAL DATE formatting characters must be remembered.

 

Format the date into a string:

Nsdateformatter formatter = [[nsdateformatter alloc] init];

[Formatter setdateformat: @ "yyyy-mm-dd"];

[Formatter settimezone: @ "H"];

Nsstring * datestring = [formatter stringfromdate: date]; // 2012-03-04 will be output.

 

 

Nsdate * earlierdate = [yesterday earlierdate: Today]; // gets the date earlier than two dates. Yesterday is returned.

Nsdate * laterdate = [tomorrow laterdate: Today]; // get the date later than the two dates. Return tomorrow

Nscalendardate * cdate = [Today datewithcalendarformat: @ "% d % B % Y" timezone: [nstimezone localtimezone]; // convert the current date to the calendardate of the specified time zone based on the format string

 

Timeinternvalsincedate // This method is used to subtract two dates.