คีย์เวิร์ด PHP
คีย์เวิร์ด PHP
PHP มีชุดของคำสำคัญที่สงวนไว้ซึ่งไม่สามารถใช้เป็นชื่อฟังก์ชัน ชื่อคลาส หรือชื่อเมธอด ก่อนหน้า PHP 7 คำหลักเหล่านี้ไม่สามารถใช้เป็นชื่อคุณสมบัติคลาสได้เช่นกัน:
| Keyword | Description |
|---|---|
| abstract | Declare a class as abstract |
| and | A logical operator |
| as | Used in the foreach loop |
| break | Break out of loops and switch statements |
| callable | A data type which can be executed as a function |
| case | Used in the switch conditional |
| catch | Used in the try..catch statement |
| class | Declare a class |
| clone | Create a copy of an object |
| const | Define a class constant |
| continue | Jump to the next iteration of a loop |
| declare | Set directives for a block of code |
| default | Used in the switch statement |
| do | Create a do...while loop |
| echo | Output text |
| else | Used in conditional statements |
| elseif | Used in conditional statements |
| empty | Check if an expression is empty |
| enddeclare | End a declare block |
| endfor | End a for block |
| endforeach | End a foreach block |
| endif | End an if or elseif block |
| endswitch | End a switch block |
| endwhile | End a while block |
| extends | Extends a class or interface |
| final | Declare a class, property or method as final |
| finally | Used in the try...catch statement |
| fn | Declare an arrow function |
| for | Create a for loop |
| foreach | Create a foreach loop |
| function | Create a function |
| global | Import variables from the global scope |
| goto | Jump to a line of code |
| if | Create a conditional statement |
| implements | Implement an interface |
| include | Embed code from another file |
| include_once | Embed code from another file |
| instanceof | Test an object's class |
| insteadof | Resolve conflicts with traits |
| interface | Declare an interface |
| isset | Check if a variable exists and is not null |
| list | Assigns array elements into variables |
| namespace | Declares a namespace |
| new | Creates an object |
| or | A logical operator |
| Output text | |
| private | Declare a property, method or constant as private |
| protected | Declare a property, method or constant as protected |
| public | Declare a property, method or constant as public |
| require | Embed code from another file |
| require_once | Embed code from another file |
| return | Exit a function and return a value |
| static | Declare a property or method as static |
| switch | Create a switch block |
| throw | Throw an exception |
| trait | Declare a trait |
| try | Create a try...catch structure |
| unset | Delete a variable or array element |
| use | Use a namespace |
| var | Declare a variable |
| while | Create a while loop or end a do...while loop |
| xor | A logical operator |
| yield | Used in generator functions |
| yield from | Used in generator functions |