In PHP
, there are two data types for numbers: Integer
integer type and Float
floating point type. In some special circumstances, we can only use integer types, and for floating point types, we can only convert them to integer types. PHP
provides the round()
function , can help us accomplish this task, this article will take you to take a look.
First of all, I must take you to take a look at the syntax of the round()
function.
round ( float $val , int $precision = 0 , int $mode = PHP_ROUND_HALF_UP )
$val: Floating point data to be converted
$precision: Optional, the number of decimal digits after the decimal point .
- ##$mode: optional, PHP_ROUND_HALF_UP, PHP_ROUND_HALF_DOWN, PHP_ROUND_HALF_EVEN or PHP_ROUND_HALF_ODD
- Return value: Return a
float
type Number
1. Only one parameter:
<?php echo round(6.1)."、"; echo round(6.2)."、"; echo round(6.3)."、"; echo round(6.4)."、"; echo round(6.5)."、"; echo round(6.6)."、"; echo round(6.64)."<br>";
输出:6、6、6、6、7、7、7
2. There are two parameters:
<?php echo round(6.4545,3)."、"; echo round(6.4545,2)."、"; echo round(6.4545,1)."、"; echo round(6.4545,0)."<br>"; ?>
输出:6.455、6.45、6.5、6
3. Three parameters:
<?php echo round(6.65,1,PHP_ROUND_HALF_DOWN)."<br>";//向下取整 echo round(6.65,1,PHP_ROUND_HALF_UP)."<br>";//向上取整 echo round(6.55,1,PHP_ROUND_HALF_EVEN)."<br>";//遇到 .5 的情况时取下一个偶数值舍入$val到 $precision小数位。 echo round(6.55,1,PHP_ROUND_HALF_ODD)."<br>";//遇到 .5 的情况时取下一个奇数值舍入$val到 $precision小数位。 ?>
输出:6.6 6.7 6.6 6.5
Recommended: 《2021 PHP interview questions summary (collection)》《php video tutorial》
The above is the detailed content of Detailed explanation of round() function in PHP. For more information, please follow other related articles on the PHP Chinese website!

ThesecrettokeepingaPHP-poweredwebsiterunningsmoothlyunderheavyloadinvolvesseveralkeystrategies:1)ImplementopcodecachingwithOPcachetoreducescriptexecutiontime,2)UsedatabasequerycachingwithRedistolessendatabaseload,3)LeverageCDNslikeCloudflareforservin

You should care about DependencyInjection(DI) because it makes your code clearer and easier to maintain. 1) DI makes it more modular by decoupling classes, 2) improves the convenience of testing and code flexibility, 3) Use DI containers to manage complex dependencies, but pay attention to performance impact and circular dependencies, 4) The best practice is to rely on abstract interfaces to achieve loose coupling.

Yes,optimizingaPHPapplicationispossibleandessential.1)ImplementcachingusingAPCutoreducedatabaseload.2)Optimizedatabaseswithindexing,efficientqueries,andconnectionpooling.3)Enhancecodewithbuilt-infunctions,avoidingglobalvariables,andusingopcodecaching

ThekeystrategiestosignificantlyboostPHPapplicationperformanceare:1)UseopcodecachinglikeOPcachetoreduceexecutiontime,2)Optimizedatabaseinteractionswithpreparedstatementsandproperindexing,3)ConfigurewebserverslikeNginxwithPHP-FPMforbetterperformance,4)

APHPDependencyInjectionContainerisatoolthatmanagesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itactsasacentralhubforcreatingandinjectingdependencies,thusreducingtightcouplingandeasingunittesting.

Select DependencyInjection (DI) for large applications, ServiceLocator is suitable for small projects or prototypes. 1) DI improves the testability and modularity of the code through constructor injection. 2) ServiceLocator obtains services through center registration, which is convenient but may lead to an increase in code coupling.

PHPapplicationscanbeoptimizedforspeedandefficiencyby:1)enablingopcacheinphp.ini,2)usingpreparedstatementswithPDOfordatabasequeries,3)replacingloopswitharray_filterandarray_mapfordataprocessing,4)configuringNginxasareverseproxy,5)implementingcachingwi

PHPemailvalidationinvolvesthreesteps:1)Formatvalidationusingregularexpressionstochecktheemailformat;2)DNSvalidationtoensurethedomainhasavalidMXrecord;3)SMTPvalidation,themostthoroughmethod,whichchecksifthemailboxexistsbyconnectingtotheSMTPserver.Impl


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

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

SublimeText3 Chinese version
Chinese version, very easy to use

SublimeText3 Mac version
God-level code editing software (SublimeText3)
