Summary of methods for obtaining time in PHP (detailed examples)
In the previous article, I brought you "How to complete the time zone setting in PHP? 》, which introduces you to several methods on how to set the time zone in PHP. In this article, we will continue to take a look at the relevant knowledge of PHP. How should we get the current time in PHP? I hope it will be helpful to everyone. help!
In the date and time functions in PHP, if we want to get the current time, we need to understand what a UNIX timestamp is.
UNIX timestamp represents the total number of seconds since 0:00:00 (Greenwich Mean Time) on January 1, 1970 to the current moment. Let me introduce to you several functions that can get the current time
<strong><span style="font-size: 18px;">time()</span></strong>
Function
The time() function is the simplest function to get the current time. It can return the UNIX timestamp of the current time. An example is as follows:
<?php echo time(); ?>
When I run the function, the time is around 10:50 on October 21, 2021, and the output is as follows:
<strong><span style="font-size: 18px;">mktime()</span></strong>
Function
mktime(指定时间时,指定时间分,指定时间秒,指定时间月,指定时间日,指定时间年)The parameters of this function can be omitted from right to left, any Omitted arguments are set to the current local date and time values. Get the UNIX timestamp of the current time, the example is as follows:
<?php echo mktime(); // 没有设置参数则默认取得当前GMT时间 ?>Output result:
<?php echo mktime(11,0,0,10,21,2021); //设置参数表示GMT时间2021年10月21日11点0分0秒 ?>Output result:
-
##gmmktime() function can also obtain the GMT date. UNIX timestamp, its syntax format is as follows:##gmmktime()<strong><span style="font-size: 18px;"></span></strong>
Function
gmmktime(指定时间时,指定时间分,指定时间秒,指定时间月,指定时间日,指定时间年)Like mktime, it can be omitted from right to left. Any omitted parameters will be set to the current value of the local date.
The example is as follows:
<?php echo gmmktime(); //没有设置参数, 则默认取得当前GMT时间 ?>Output result:
It can be seen from the above example that when all parameters are omitted Finally, the parameters are set to the parameters of the current time in the current time zone, so the UNIX timestamp of the current time is output.
<?php echo gmmktime(0,0,0,10,21,2021); ?>Output result:
As can be seen from the above example, the UNIX timestamp of the specified time can be obtained through the gmmktime() function.
- ##microtime()
<strong><span style="font-size: 18px;"></span>Function</strong>
The microtime() function can return the number of microseconds of the current UNIX timestamp. Its syntax is as follows:microtime ($get_as_float )
The example is as follows:
<?php echo microtime(); ?>
Output result:
Although the microtime function can display more detailed microseconds, it doesn't look very good. Is there any way to visually see the microseconds?
We can set the parameter behind the microtime function to true through the parameter settings behind the function, then a floating-point string will be returned to represent the time.
The example is as follows:
<?php echo microtime(true); //返回一个浮点型字符串表示时间 ?>
Output result:
- ##getdate()
<strong>## Function <span style="font-size: 18px;"></span></strong>
我们前面介绍了这么多的函数都能够获取当前的时间或者指定的时间的UNIX时间戳,getdate函数就比较厉害了,他可以取得日期时间信息。它的语法格式如下:
array getdate ([ int $timestamp = time() ] )
简单来说,getdate函数能够根据参数的信息返回一个关联数组,这个数组中包含了很多元素,下面给大家列举一下:
seconds
---表示秒的数字minutes
---表示分钟的数字hours
---表示小时的数字mday
---表示月份中第几天的数字wday
---星期中第几天的数字mon
---表示月份中第几个月的数字year
---用4 位数字表示的完整年份yday
---表示一年中第几天的数字weekday
---表示星期几的英文month
---表示月份的英文0
---表示自从 UNIX 纪元开始至今的秒数
示例如下:
<?php echo "<pre class="brush:php;toolbar:false">"; var_dump(getdate()); ?>
输出结果:
由上述示例中可以看出,通过getdate函数,返回的数组中包含了当前时间的相关信息。
大家如果感兴趣的话,可以点击《PHP视频教程》进行更多关于PHP知识的学习。
The above is the detailed content of Summary of methods for obtaining time in PHP (detailed examples). For more information, please follow other related articles on the PHP Chinese website!

PHPsessionscanstorestrings,numbers,arrays,andobjects.1.Strings:textdatalikeusernames.2.Numbers:integersorfloatsforcounters.3.Arrays:listslikeshoppingcarts.4.Objects:complexstructuresthatareserialized.

TostartaPHPsession,usesession_start()atthescript'sbeginning.1)Placeitbeforeanyoutputtosetthesessioncookie.2)Usesessionsforuserdatalikeloginstatusorshoppingcarts.3)RegeneratesessionIDstopreventfixationattacks.4)Considerusingadatabaseforsessionstoragei

Session regeneration refers to generating a new session ID and invalidating the old ID when the user performs sensitive operations in case of session fixed attacks. The implementation steps include: 1. Detect sensitive operations, 2. Generate new session ID, 3. Destroy old session ID, 4. Update user-side session information.

PHP sessions have a significant impact on application performance. Optimization methods include: 1. Use a database to store session data to improve response speed; 2. Reduce the use of session data and only store necessary information; 3. Use a non-blocking session processor to improve concurrency capabilities; 4. Adjust the session expiration time to balance user experience and server burden; 5. Use persistent sessions to reduce the number of data read and write times.

PHPsessionsareserver-side,whilecookiesareclient-side.1)Sessionsstoredataontheserver,aremoresecure,andhandlelargerdata.2)Cookiesstoredataontheclient,arelesssecure,andlimitedinsize.Usesessionsforsensitivedataandcookiesfornon-sensitive,client-sidedata.

PHPidentifiesauser'ssessionusingsessioncookiesandsessionIDs.1)Whensession_start()iscalled,PHPgeneratesauniquesessionIDstoredinacookienamedPHPSESSIDontheuser'sbrowser.2)ThisIDallowsPHPtoretrievesessiondatafromtheserver.

The security of PHP sessions can be achieved through the following measures: 1. Use session_regenerate_id() to regenerate the session ID when the user logs in or is an important operation. 2. Encrypt the transmission session ID through the HTTPS protocol. 3. Use session_save_path() to specify the secure directory to store session data and set permissions correctly.

PHPsessionfilesarestoredinthedirectoryspecifiedbysession.save_path,typically/tmponUnix-likesystemsorC:\Windows\TemponWindows.Tocustomizethis:1)Usesession_save_path()tosetacustomdirectory,ensuringit'swritable;2)Verifythecustomdirectoryexistsandiswrita


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Dreamweaver Mac version
Visual web development tools

WebStorm Mac version
Useful JavaScript development tools

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
