PHP 数组与方法和变量声明中的 []
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PHP array vs [ ] in method and variable declaration
提问by Dieter Gribnitz
I have a question about PHP syntax.
我有一个关于 PHP 语法的问题。
When defining functions and variables, which convention should I use?
定义函数和变量时，应该使用哪种约定？
I know they do the same thing in practice but I would like to know which method conforms to best practice standards.
我知道他们在实践中做同样的事情，但我想知道哪种方法符合最佳实践标准。
Variables
变量
public $varname = array();
or
或者
public $varname = [];
Methods
方法
public function foo($bar = array()){}
or
或者
public function foo($bar = []){}
回答by BreyndotEchse
PSR-2(by PHP Framework Interoperability Group) does not mention short array syntax. But as you can see in chapter 4.3they use short array syntax to set the default value of $arg3to be an empty array.
PSR-2（由PHP Framework Interoperability Group 提供）没有提到短数组语法。但是正如您在第 4.3 章中看到的，它们使用短数组语法将 的默认值设置为$arg3空数组。
So for PHP >= 5.4 the short array syntax seems to be the de-facto standard. Only use array(), if you want your script to run on PHP <5.4.
所以对于 PHP >= 5.4，短数组语法似乎是事实上的标准。array()如果您希望脚本在 PHP <5.4 上运行，请仅使用。
回答by Nitsan Baleli
from PHP docs:
来自 PHP文档：
As of PHP 5.4 you can also use the short array syntax, which replaces array() with [].
从 PHP 5.4 开始，您还可以使用短数组语法，它将 array() 替换为 []。
<?php
$array = array(
"foo" => "bar",
"bar" => "foo",
);
// as of PHP 5.4
$array = [
"foo" => "bar",
"bar" => "foo",
];
?>
if you'd try using '[]' notation in earlier version than 5.4, it will fail, and PHP will throw a syntax error
如果您尝试在 5.4 之前的版本中使用 '[]' 表示法，它将失败，并且 PHP 将抛出一个 syntax error
for backward-compatibility you should use array()syntax.
为了向后兼容，您应该使用array()语法。
回答by Valentin Rodygin
That depends on what version of PHP you are targeting. For the best backward compatibility, I'd recommend you to use array(). If you don't care about older versions (< PHP 5.4), I'd recommend you to use a shorter version.
这取决于您所针对的 PHP 版本。为了获得最佳的向后兼容性，我建议您使用 array()。如果您不关心旧版本（< PHP 5.4），我建议您使用较短的版本。
回答by Aurangzeb
just made a test to see how [] performs vs array() here is what I got
刚刚做了一个测试，看看 [] 如何执行 vs array() 这就是我得到的
testing 1 million []s ( with $arr[] = [] )
started at : 1561298821.8754
ended at: 1561298822.6881
difference: 0.81266021728516 seconds
testing 1 million array()s ( with array_push( $arr, array()) )
started at : 1561298822.6881
ended at: 1561298823.843
difference: 1.1549289226532 seconds
testing 1 million []s ( again while the processor is hotter)
started at : 1561298823.8431
ended at: 1561298824.7448
difference: 0.9017219543457 seconds
so [] performed about 20% faster
所以 [] 的执行速度提高了大约 20%
