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问题描述

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我通常使用 PHP从变量数组建设紧凑型()功能。另外,我可以手动创建数组。有那些用途的任何优点或缺点?我分享双方在以下段这些声明的例子:

紧凑型用法

 < PHP
    $名称=约翰;
    $姓=李四;
    紧凑的('名','姓');
?>

输出:

  ['名'=>'约翰','姓'=>'李四']


手册数组声明

 < PHP
$名称=约翰;
$姓=李四;
$数据=阵列(名= GT; $名字,姓= GT; $姓);
?>

输出:

  ['名'=>'约翰','姓'=>'李四']


解决方案

我觉得它更preference的问题。

使用

如果我有一堆局部变量的声明,我正好希望我的数组键被命名为同样的方式,紧凑是很有帮助的。

我不觉得这是如此经常虽然。通常情况下,我定义的数组,它是更为复杂的:

  $阵列= [
    '富'=> $ something->富()
    '酒吧'=> $吧,
    巴兹'=> A_CONSTANT
];

要使用紧凑在这里你必须定义变量 $ foo的 $酒吧 $巴兹第一,这似乎是愚蠢的。

我喜欢紧凑,我不觉得这是各地有益的大部分时间。

性能

好吧,我不得不去做到这一点。这里是一个非常基本的非科学的绩效对比:

总之,使用紧凑是一个量级慢。

然而,你必须使用它100,000(在这个例子中)要重要的一秒钟的一小部分。

在换句话说,使用什么最有意义您code。不要担心了令人难以置信的小的性能差异!

I am usually using compact() function of php for the building array from the variables. Also, I can create that array manually. Are there any pros or cons of those usages? I am sharing an examples both of those declarations on the following segment:

Compact Usage

   <?php
    $name = "John";
    $surname = "Doe";
    compact('name','surname');
?>

Output:

['name'=>'John','surname'=>'Doe']


Manual Array Declaration

<?php
$name = "John";
$surname = "Doe";
$data = array("name"=>$name,"surname"=>$surname);
?>

Output:

['name'=>'John','surname'=>'Doe']
解决方案

I think it's more a matter of preference.

Uses

If I have a bunch of local variables declared, and I happen to want my array keys to be named the same way, compact is very helpful.

I don't find that to be the case very often though. Typically I'm defining an array that is more complex:

$array = [
    'foo' => $something->foo(),
    'bar' => $bar,
    'baz' => A_CONSTANT
];

To use compact here you'd have to define your variables $foo $bar and $baz first, which seems silly.

I like compact, I just don't find it to be all around helpful most of the time.

Performance

Ok I had to go do it. Here's a very basic non-scientific performance comparison:

https://3v4l.org/WTrOJ

In short, using compact is an order of magnitude slower.

And yet, you have to use it 100,000 (in this example) to matter a tiny fraction of a second.

In other words: use what makes the most sense for your code. Don't worry about the incredibly small performance difference!

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09-08 14:28