[英]PHP - How to search an associative array by matching the key against a regexp
I am currently working on a small script to convert data coming from an external source. 我目前正在研究一个小的脚本,以转换来自外部源的数据。 Depending on the content I need to map this data to something that makes sense to my application.
根据内容,我需要将此数据映射到对我的应用程序有意义的内容。
A sample input could be: 输入示例可以是:
$input = 'We need to buy paper towels.'
Currently I have the following approach: 目前,我有以下方法:
// Setup an assoc_array what regexp match should be mapped to which itemId
private $itemIdMap = [ '/paper\stowels/' => '3746473294' ];
// Match the $input ($key) against the $map and return the first match
private function getValueByRegexp($key, $map) {
$match = preg_grep($key, $map);
if (count($match) > 0) {
return $match[0];
} else {
return '';
}
}
This raises the following error on execution: 这会在执行时引发以下错误:
Warning: preg_grep(): Delimiter must not be alphanumeric or backslash
警告:preg_grep():分隔符不得为字母数字或反斜杠
What am I doing wrong and how could this be solved? 我在做什么错,这怎么解决?
In preg_grep
manual order of arguments is: 在
preg_grep
,参数的手动顺序为:
string $pattern , array $input
In your code $match = preg_grep($key, $map);
在您的代码中
$match = preg_grep($key, $map);
- $key
is input string, $map
is a pattern. -
$key
是输入字符串, $map
是模式。
So, your call is 所以,你的电话是
$match = preg_grep(
'We need to buy paper towels.',
[ '/paper\stowels/' => '3746473294' ]
);
So, do you really try to find string We need to buy paper towels
in a number 3746473294
? 那么,您真的尝试找到线吗?
We need to buy paper towels
数量3746473294
吗?
So first fix can be - swap'em and cast second argument to array
: 因此,第一个解决方法是 -swap'em并将第二个参数转换为
array
:
$match = preg_grep($map, array($key));
But here comes second error - $itemIdMap
is array. 但是这是第二个错误-
$itemIdMap
是数组。 You can't use array as regexp. 您不能将数组用作正则表达式。 Only scalar values (more strictly - strings) can be used.
只能使用标量值(更严格地说是字符串)。 This leads you to:
这将导致您:
$match = preg_grep($map['/paper\stowels/'], $key);
Which is definitely not what you want, right? 绝对不是您想要的,对吗?
The solution : 解决方案 :
$input = 'We need to buy paper towels.';
$itemIdMap = [
'/paper\stowels/' => '3746473294',
'/other\sstuff/' => '234432',
'/to\sbuy/' => '111222',
];
foreach ($itemIdMap as $k => $v) {
if (preg_match($k, $input)) {
echo $v . PHP_EOL;
}
}
Your wrong assumption is that you think you can find any item from array of regexps in a single string with preg_grep
, but it's not right. 错误的假设是您认为可以使用
preg_grep
在单个字符串中preg_grep
数组中的任何项,但这是不对的。 Instead, preg_grep
searches elements of array, which fit one single regexp. 相反,
preg_grep
搜索适合单个正则表达式的数组元素。 So, you just used the wrong function. 因此,您只是使用了错误的功能。
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