Time类表示日期和时间。它是操做系统提供的系统日期和时间之上的。 这个类有可能在你的系统上不能表示1970以前或2038以后的日期。html
#!/usr/bin/ruby -w time1 = Time.new puts "Current Time : " + time1.inspect # Time.now is a synonym: time2 = Time.now puts "Current Time : " + time2.inspect
结果：数组
zzl@zzl-VirtualBox:~/rubyprojects$ ruby demo_time.rb Current Time : 2019-11-27 02:44:56 +0800 Current Time : 2019-11-27 02:44:56 +0800
demo_timeComponents.rbruby
time = Time.new # Components of a Time puts "Current Time : " + time.inspect puts "year=" + time.year.to_s # => Year of the date puts "month=" + time.month.to_s # => Month of the date (1 to 12) puts "day=" + time.day.to_s # => Day of the date (1 to 31 ) puts "wday=" + time.wday.to_s # => 0: Day of week: 0 is Sunday puts "yday=" + time.yday.to_s # => 365: Day of year puts "hour=" + time.hour.to_s # => 23: 24-hour clock puts "min=" + time.min.to_s # => 59 puts "sec=" + time.sec.to_s # => 59 puts "ms=" + time.usec.to_s # => 999999: microseconds puts "timezone=" + time.zone # => "UTC": timezone name
结果：函数
zzl@zzl-VirtualBox:~/rubyprojects$ ruby demo_timeComponent.rb Current Time : 2019-11-27 03:00:52 +0800 year=2019 month=11 day=27 wday=3 yday=331 hour=3 min=0 sec=52 ms=804903 timezone=CST
utc,gm ,local 函数能够来格式化时间。以下：操作系统
# July 8, 2008 Time.local(2008, 7, 8) # July 8, 2008, 09:10am, local time Time.local(2008, 7, 8, 9, 10) # July 8, 2008, 09:10 UTC Time.utc(2008, 7, 8, 9, 10) # July 8, 2008, 09:10:11 GMT (same as UTC) Time.gm(2008, 7, 8, 9, 10, 11)
能够获取如下格式的日期时间信息：code
[sec,min,hour,day,month,year,wday,yday,isdst,zone]
time = Time.new values = time.to_a p values
结果：orm
[40, 8, 3, 27, 11, 2019, 3, 331, false, "CST"]
htm
这个数组能够传给 Time.utc 或Time.local 来格式化：对象
time = Time.new values = time.to_a puts Time.utc(*values)
结果：索引
2019-11-27 03:10:41 UTC 如下是从epoch开始的秒数（取决于平台）：
# Returns number of seconds since epoch time = Time.now.to_i # Convert number of seconds into Time object. Time.at(time) # Returns second since epoch which includes microseconds time = Time.now.to_f
你能够用Time 对象获取与Timezones 和 Daylight savings 的全部信息。
time = Time.new # Here is the interpretation time.zone # => "UTC": return the timezone time.utc_offset # => 0: UTC is 0 seconds offset from UTC time.zone # => "PST" (or whatever your timezone is) time.isdst # => false: If UTC does not have DST. time.utc? # => true: if t is in UTC time zone time.localtime # Convert to local timezone. time.gmtime # Convert back to UTC. time.getlocal # Return a new Time object in local zone time.getutc # Return a new Time object in UTC
有不一样方法能够格式化日期和时间。举例
time = Time.new
puts time.to_s
puts time.ctime
puts time.localtime
puts time.strftime("%Y-%m-%d %H:%M:%S")
结果
zzl@zzl-VirtualBox:~/rubyprojects$ ruby demo_timeformat.rb 2019-11-27 03:17:18 +0800 Wed Nov 27 03:17:18 2019 2019-11-27 03:17:18 +0800 2019-11-27 03:17:18
| Sr.No. | Directive & Description |
|---|---|
| 1 | %a The abbreviated weekday name (Sun). 英文星期缩写 |
| 2 | %A The full weekday name (Sunday). 英文星期全名 |
| 3 | %b The abbreviated month name (Jan). 英文月份缩写 |
| 4 | %B The full month name (January). 英文月全名 |
| 5 | %c The preferred local date and time representation. 当地日期和时间表示 |
| 6 | %d Day of the month (01 to 31). 每个月的天，即几号。 |
| 7 | %H Hour of the day, 24-hour clock (00 to 23). 小时，24小时制（00-23） |
| 8 | %I Hour of the day, 12-hour clock (01 to 12). 小时， 12小时制（01-12） |
| 9 | %j Day of the year (001 to 366). 天（001-366） |
| 10 | %m Month of the year (01 to 12). 月（01-12） |
| 11 | %M Minute of the hour (00 to 59). 分（00-59） |
| 12 | %p Meridian indicator (AM or PM). 上下午 |
| 13 | %S Second of the minute (00 to 60). 秒（00-60） |
| 14 | %U Week number of the current year, starting with the first Sunday as the first day of the first week (00 to 53). 当年的第几周，以第一个星期天为第一周的第一天（00-53） |
| 15 | %W Week number of the current year, starting with the first Monday as the first day of the first week (00 to 53). 当年周数，以第一个星期一做为第一周的第一天 （00-53） |
| 16 | %w Day of the week (Sunday is 0, 0 to 6). 周几。 （0-6） |
| 17 | %x Preferred representation for the date alone, no time. 日期，没有时间 |
| 18 | %X Preferred representation for the time alone, no date. 时间，没有日期。 |
| 19 | %y Year without a century (00 to 99). 最后俩位年 |
| 20 | %Y Year with century. 四位年 |
| 21 | %Z Time zone name. 时间带名字 |
| 22 | %% Literal % character. % |
时间能够+，-。举例：
now = Time.now # Current time puts now past = now - 10 # 10 seconds ago. Time - number => Time puts past future = now + 10 # 10 seconds from now Time + number => Time puts future diff = future - past # => 10 Time - Time => number of seconds puts diff
结果
zzl@zzl-VirtualBox:~/rubyprojects$ ruby demo_timeArithmetic.rb 2019-11-27 03:21:18 +0800 2019-11-27 03:21:08 +0800 2019-11-27 03:21:28 +0800 20.0
迭代器依次返回集合中全部成员。 介绍一下each 和 collect.
each {|item| block} → ary
each → Enumerator
将每一个元素都传给block执行，返回本身。
若是没有block ,则返回枚举器。
a = [ "a", "b", "c" ]
b=a.each {|x| print x, " -- " }
puts "\n"
p b
结果：
ruby demo_each.rb a -- b -- c -- ["a", "b", "c"]
each_index {|index| block} → ary
each_index → Enumerator
和each 相似，不过它传的是元素的索引，而不是元素。
若是没有block ,则返回枚举器。
collect {|item| block} → new_ary
collect → Enumerator
将每个元素都执行block，返回一个数组包含block返回的值。
若是没有block， 返回一个枚举器。
a = [ "a", "b", "c", "d" ]
a.collect {|x| x + "!"} #=> ["a!", "b!", "c!", "d!"]
a.map.with_index {|x, i| x * i} #=> ["", "b", "cc", "ddd"]
a #=> ["a", "b", "c", "d"]
collect! {|item| block } → ary
collect! → Enumerator
将每个元素都执行block，替换原来的元素。
若是没有block， 返回一个枚举器。
a = [ "a", "b", "c", "d" ]
a.map! {|x| x + "!" }
a #=> [ "a!", "b!", "c!", "d!" ]
a.collect!.with_index {|x, i| x[0...i] }
a #=> ["", "b", "c!", "d!"]