在php中的关联数组中初始化元素是否是一种好习惯? [英] Is it good practice to initialize the elements in an associative array in php?

问题描述

我发现自己在PHP中使用关联数组做很多事情.

I'm finding myself doing a lot of things with associative arrays in PHP.

我正在这样做:

 foreach ($item as $key=>$value) {
     if ($arr[$key] == null) {
         $arr[$key] = 0; 
     }
     $arr[$key] += $other_arr[$value];
 }

但是后来我意识到，如果我排除初始化$ arr [$ key]的行，那可能很好用，大概是因为它为null，它被视为与0相同.

But then I realised that it works fine if I exclude the line that initializes $arr[$key], presumably since it's null which is treated as the same as 0.

在php中使这种假设安全吗?如果安全的话，这是个好主意吗?

Is making that kind of assumption safe in php? And if it's safe, is it a good idea?

推荐答案

这是安全的，但我建议不要这样做. 如果您将错误报告提高到E_NOTICES，您将看到代码产生了大量错误，从而掩盖了所有实际错误(例如，错误键入的变量名).

It is safe but I'd recommend against it. If you put your error reporting up to E_NOTICES you'll see your code producing a lot of them, masking any real errors (such as a mistyped variable name).

您真正应该做的是:

if (!isset($arr[$key]))
    $arr[$key] = 0;

这不会引起通知(但请注意不要在isset()中错误键入$ arr).

This won't raise a notice (but be very careful not to mis-type $arr inside isset()).

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