这个符号在PHP中是什么意思?

这是一组时不时出现的关于PHP语法的问题。这也是一个社区Wiki,因此邀请每个人都参与维护此列表。

为什么会这样?

以前很难找到关于运算符和其他语法标记的问题。

注:自2013年1月起,堆栈溢出 does support special characters . 只要用引号把搜索词括起来,例如。 [php] "==" vs "==="

如果你在这里被人指是因为你问了这样一个问题,请找出下面的特定语法。链接到 PHP manual

名单

如果您的特定令牌未在下面列出,您可能会在 List of Parser Tokens .

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& Bitwise Operators 或 References

• What does it mean to start a PHP function with an ampersand?
• Understanding PHP & (ampersand, bitwise and) operator
• PHP "&" operator
• Difference between & and && in PHP
• What does "&" mean here in PHP?
• What does "&" mean in this case?
• What does the "&" sign mean in PHP?
• What does this signature mean (&) in PHP?
• How does the "&" operator work in a PHP function?
• What does & in &2 mean in PHP?
• When should I use a bitwise operator?
• Is there ever a need to use ampersand in front of an object?

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=& 工具书类

• Reference assignment operator in PHP, =&
• What do the "=&" and "&=" operators in PHP mean?
• What do the '&=' and '=&' operators do?
• What does =& mean in PHP?

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&=

• PHP中的“=”和“&=”运算符是什么意思?
• “&=”和“=&”运算符做什么?

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&& Logical Operators

• 'AND' vs '&&' as operator
• PHP中的&和&之间的差异
• Is there any difference between "and" and "&&" operators in PHP?
• PHP - and / or keywords

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% Arithmetic Operators

• What does the percent sign mean in PHP?
• What is the PHP operator % and how do I use it in real-world examples?

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!!

• Double not (!!) operator in PHP

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@ Error Control Operators

• What is the use of the @ symbol in PHP?
• 'At' symbol before variable name in PHP: @$_POST
• PHP functions and @functions
• Should I use @ in my PHP code?
• What does @ mean in PHP?

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?: Ternary Operator

• What are the PHP operators "?" and ":" called and what do they do?
• ?: operator (the 'Elvis operator') in PHP
• Where can I read about conditionals done with "?" and ":" (colon)?
• Using PHP 5.3 ?: operator

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?? Null Coalesce Operator (自PHP 7起)

• C#'s null coalescing operator (??) in PHP

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?string ?int ?array ?bool ?float Nullable return type declaration (自PHP 7.1起)

• Nullable return type declaration
• php method argument type hinting with question mark (?type)

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: Alternative syntax for control structures , 三元运算符

• What is ":" in PHP?
• What does ":" mean in PHP?

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:: Scope Resolution Operator

• What do two colons mean in PHP?
• What's the meaning of the PHP token name T_PAAMAYIM_NEKUDOTAYIM?
• What's the difference between :: (double colon) and -> (arrow) in PHP?
• What exactly are late static bindings in PHP?
• static::staticFunctionName()
• Unexpected T_PAAMAYIM_NEKUDOTAYIM, expecting T_NS_Separator

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\ Namespaces

• Backslash in PHP -- what does it mean?
• What does a \ (backslash) do in PHP (5.3+)?

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-> Classes And Objects

• What is the "->" PHP operator called?
• Where do we use the object operator "->" in PHP?
• PHP中的::(双冒号)和->(箭头)有什么区别?
• What does the PHP syntax $var1->$var2 mean?
• What does "->" mean/refer to in PHP?

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=> Arrays

• What does "=>" mean in PHP?
• Use of => in PHP
• What does $k => $v in foreach($ex as $k=>$v) mean?

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^ 位运算符

• How does the bitwise operator XOR ('^') work?
• What does ^ mean in PHP?

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>> 位运算符

• What does >> mean in PHP?

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<<

• Strange print behaviour in PHP?

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<<< Heredoc or Nowdoc

• What does <<<END mean in PHP?
• PHP expression <<<EOB
• In PHP, what does "<<<" represent?
• Using <<<CON in PHP
• What's this kind of syntax in PHP?

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= Assignment Operators

• The 3 different equals

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== Comparison Operators

• How do the PHP equality (== double equals) and identity (=== triple equals) comparison operators differ?
• PHP != and == operators
• 三个不同的相等
• Type-juggling and (strict) greater/lesser-than comparisons in PHP

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=== 比较运算符

• What does "===" mean?
• 三个不同的相等
• 在PHP中输入jugging和(严格的)大于/小于比较

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!== 比较运算符

• What does !== comparison operator in PHP mean?
• Is there a difference between !== and != in PHP?

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!=

• 两者有区别吗!==还有!=在PHP中?
• comparing, !== versus !=
• What is the difference between <> and !=

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<> 比较运算符

• PHP operator <>
• PHP's <> operator
• What is the difference between <> and !=
• 在PHP中输入jugging和(严格的)大于/小于比较

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<=> 比较运算符 (自PHP 7.0以来)

• Spaceship (three way comparison) operator

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| 位运算符

• What is the difference between the | and || operators?
• What Does Using A Single Pipe '|' In A Function Argument Do?

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|| 逻辑运算符

• |运算符和| |运算符之间有什么区别?
• What exactly does || mean?
• The behaviour of the or operator in PHP

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~ 位运算符

• What does this ~ operator mean here?

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+ 算术运算符 , Array Operators

• + operator for array in PHP?

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+= 和 -= 赋值运算符

• What is += used for?
• What does `$page -= 1` in my PHP document mean?

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++ 和 -- Incrementing/Decrementing Operators

• Understanding Incrementing
• Answer below

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.= 赋值运算符

• What is the difference between .= and += in PHP?
• To understand a line of PHP

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. String Operators

• Difference between period and comma when concatenating with echo versus return?
• What does a . (dot) do in PHP?

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, Function Arguments

• 与echo和return连接时句点和逗号之间的区别?

, Variable Declarations

• What do commas mean in a variable declaration?

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$$ Variable Variables

• What does $$ (dollar dollar or double dollar) mean in PHP?
• what is "$$" in PHP
• $function() and $$variable

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` Execution Operator

• What are the backticks `` called?

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<?= Short Open Tags

• What does this symbol mean in PHP <?=
• What does '<?=' mean in PHP?
• What does <?= mean?

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[] 数组 (自PHP 5.4以来的简短语法)

• PHP arrays... What is/are the meaning(s) of an empty bracket?
• What is the meaning of []
• Php array_push() vs myArray[]
• What does [] mean when reading from a PHP array?
• Shorthand for arrays: literal $var = [] empty array

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<? Opening and Closing tags

• Are PHP short tags acceptable to use?

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... Argument unpacking (自PHP 5.6起)

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** Exponentiation (自PHP 5.6起)

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# One-line shell-style comment

• Can I use hashes for comments in PHP?

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?-> NullSafe Operator Calls

• What does this symbol mean "?->" in php, within an object or null value

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