仅当在数组A中找不到数组时才返回数组的键 [英] Return keys of array only if not found in array A

问题描述

我有两个数组，一个是自定义的.

I have two arrays one is self defined.

$fields = array( "first_name" => "test", "last_name" => "Test", "phone" =>"111-111-1111, "id" => 1234");

另一个是从csv文件的第一行中获取的.它将返回一个像这样的数组

the other is grabbed from the first row of a csv file. which will return an array like so

$headers = array ("fname" => "test", "last_name" => "Test", "phone"=> "123-123-1234");

然后，如果$ headers数组中的键与$ fields数组中的任何键都不匹配，我想返回一个错误.如果$ fields数组中的键不是全部出现在$ headers数组中，也可以.

I then want to return an error if there is a key in $headers array doesn't match any of the keys in $fields array. Its okay if the keys in the $fields array aren't all present in the $headers array.

例如，上面的两个数组应该返回错误，因为键fname在$ fields数组中不存在，而不是因为id在$ headers数组中缺失.

For example the two arrays above should return an error because the key fname does not exist in the $fields array but not because the id is missing in the $headers array.

我尝试使用带有多个循环的if语句进行试验，但是我正在寻找一种更好的方法，我认为我可以操纵array_diff方法，但是没有运气.

I tried experimenting with if statements with multiple loops but I am looking for a better way I thought I could manipulate the array_diff method but have had no luck.

$dif_keys = array_diff($fields, $headers);

推荐答案

两件事:

1. 如果要检查 $ headers 中是否所有键是否存在于 $ fields 中，请使用 array_diff_key 而不是 array_diff . array_diff 将仅比较值.

1. If you want to check if all keys from $headers are present in $fields, use array_diff_key instead of array_diff. array_diff will only compare values.

更改参数的顺序.diff函数返回后一个参数中不存在的第一个参数的值，因此如果 $ fields 包含一些不在 $ headers中的键无关紧要，您要先放置 $ headers .

Change the order of the arguments. The diff functions return the values of the first argument that aren't present in the subsequent arguments, so if it doesn't matter that $fields has some keys that aren't in $headers, you want to put $headers first.

所以我认为您需要的代码是:

So I think the code you need is:

$diff = array_diff_key($headers, $fields);

您可以将 $ diff 评估为布尔值.(例如 if($ diff){... )如果为空，则将其评估为false，这意味着 $ headers 中的所有键在中均具有对应的键> $ fields .

You can evaluate $diff as a boolean. (e.g. if ($diff) {...) If it is empty, it will evaluate as false, which means all keys in $headers had corresponding keys in $fields.

这篇关于仅当在数组A中找不到数组时才返回数组的键的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！