The rules that PHP should follow to write code

Quoted in: https://zhuanlan.zhihu.com/p/33451652, thank summer God

1, use meaningful and readable variable names (be sure to define the meaning of the variable name)
Eg: $currentDate

2, use a searchable name
Eg: Defining constants in a class

3, avoid nesting too deep and returning early
Error:

1 functionIsshopopen ($day):BOOL2 {3 if($day) {4 if(is_string($day)) {5 $day=Strtolower($day);6 if($day= = = ' Friday ') {7 return true;8}ElseIf($day= = = ' Saturday ') {9 return true;Ten}ElseIf($day= = = ' Sunday ') { One return true; A}Else { - return false; - } the}Else { - return false; - } -}Else { + return false; - } +}

Correct: (Error can throw an exception)

function isshopopen (string$day): bool{if (empty($day ) {returnfalse;} $openingDays = [' Friday ', ' Saturday ', ' Sunday ']; return In_array (strtolower($day$openingDaystrue);}

4, be sure to define the type of the function variable (not conditional judgment)
Eg:public function Send (string $email, String $userName) {}

5, conditional judgment use equals character = =

6, the function parameter should be less than two parameters, it is more than three, encapsulates an object
eg:public function Send (User $user) {}

7, the function should do only one thing

8, the name of the function to say clearly what it does

9, do not use a Boolean variable as a function parameter
Unfriendly:

1 functionCreateFile (string $name, BOOL$temp=false):void2 {3 if($temp) {4 Touch('./temp/').$name);5}Else {6 Touch($name);7 }8}

Friendly to:

1 functionCreateFile (string $name):void2 {3 Touch($name);4 }5 6 functionCreatetempfile (string $name):void7 {8 Touch('./temp/').$name);9}

Note: This also conforms to the function only to do one thing

10, try not to define global functions

11, Package condition statement
Unfriendly:

if ($article->state = = = = ' published ') {
// ...
}
Friendly to:

if ($article->ispublished ()) {
// ...
}

12, avoid the use of antisense conditions to judge
Eg:if (!isdomnodenotpresent ($node))

13. Remove Useless code

14, use protected and private to describe the variables in the class

15, single principle of responsibility
Eg: as stated in the Clean Code book, "Modifying a class should be for one reason only". It's always easy to "cram" a class in a bunch of ways, as if we were going to be able to carry all the stuff into the box when we had to take a suitcase on a plane. The consequence of this is that, logically, such a class is not high cohesion and leaves a lot of reason to modify it later.
It is important to minimize the number of times you need to modify a class, because when there are many methods in a class, it is difficult to know which modules depend on it in the entire code base.

More bad:

1 classusersettings2 {3 Private $user;4 5  Public function__construct (User$user)6 {7 $this->user =$user;8 }9 Ten  Public functionChangesettings (Array $settings):void One { A if($this-verifycredentials ()) { - // ... - } the } -  - Private functionVerifycredentials ():BOOL - { + // ... - } +}

Awesome:

1 classUserauth2 {3 Private $user;4 5  Public function__construct (User$user)6 {7 $this->user =$user;8 }9 Ten  Public functionVerifycredentials ():BOOL One { A // ... - } - } the  - classusersettings - { - Private $user; + Private $auth; -  +  Public function__construct (User$user)  A { at $this->user =$user; - $this->auth =NewUserauth ($user); - } -  -  Public functionChangesettings (Array $settings):void - { in if($this->auth->verifycredentials ()) { - // ... to } + } -}

16, avoid writing duplicate code

The rules that PHP should follow to write code