PHP默认数组值，如果键不存在？ [英] PHP default array values if key doesn't exist?

问题描述

如果我有一个数组充满了信息，有什么办法，我可以，如果该键不存在值默认被返回？

If I have an array full of information, is there any way I can a default for values to be returned if the key doesn't exist?

function items() {
    return array(
        'one' => array(
              'a' => 1,
              'b' => 2,
              'c' => 3,
              'd' => 4,
         ),
         'two' => array(
              'a' => 1,
              'b' => 2,
              'c' => 3,
              'd' => 4,
         ),
         'three' => array(
              'a' => 1,
              'b' => 2,
              'c' => 3,
              'd' => 4,
         ),
    );
}

在我的code

And in my code

$items = items();
echo $items['one']['a']; // 1

不过，我可以有，如果我给一个键不存在要返回默认值一样，

But can I have a default value to be returned if I give a key that doesn't exist like,

$items = items();
echo $items['four']['a']; // DOESN'T EXIST RETURN DEFAULT OF 99

感谢？

推荐答案

我知道这是一个老问题，但我的谷歌搜索PHP数组默认值花了我这里，我想我会发布的解决方案我寻找，机会是它可能会帮助别人。

I know this is an old question, but my Google search for "php array default values" took me here, and I thought I would post the solution I was looking for, chances are it might help someone else.

我想用这可以通过自定义值覆盖默认选项值的数组。我结束了使用 array_merge 。

I wanted an array with default option values that could be overridden by custom values. I ended up using array_merge.

例如：

<?php
    $defaultOptions = array("color" => "red", "size" => 5, "text" => "Default text");
    $customOptions = array("color" => "blue", "text" => "Custom text");
    $options = array_merge($defaultOptions, $customOptions);
    print_r($options);
?>

输出：

Array
(
    [color] => blue
    [size] => 5
    [text] => Custom text
)

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