從字符串中的數組鍵替換匹配的字符串

Question

我的目標是在一個字符串中找到一個假設數組的鍵，並在該字符串中用數組中的匹配鍵替換這些鍵。

我有一個小而有用的函數，它可以在 2 個分隔符（沙盒鏈接： https : //repl.it/repls/UnlinedDodgerblueAbstractions ）之間找到我的所有字符串：

function findBetween( $string, $start, $end )
{
    $start = preg_quote( $start, '/' );
    $end = preg_quote( $end, '/' );

    $format = '/(%s)(.*?)(%s)/';

    $pattern = sprintf( $format, $start, $end );

    preg_match_all( $pattern, $string, $matches );

    $number_of_matches = is_string( $matches[2] ) ? 1 : count( $matches[2] );

    if( $number_of_matches === 1 ) {
        return $matches[2];
    }

    if( $number_of_matches < 2 || empty( $matches ) ) {
        return False;
    }

    return $matches[2];
}

例子：

findBetween( 'This thing should output _$this_key$_ and also _$this_one$_ so that I can match it with an array!', '_$', '$_')

應該像它一樣返回一個值為['this_key', 'this_one']的數組。 問題是，我怎樣才能將這些替換為關聯數組的值？

假設我的數組是這樣的：

[
    'this_key' => 'love',
    'this_one' => 'more love'
];

我的輸出應該是這樣的：

This thing should output love and also more love so that I can match it with an array!

我怎樣才能做到這一點？

Answer 1

這是一個問題，使用strtr可能比使用正則表達式更容易解決。 我們可以使用array_map在$replacements的鍵周圍添加$start和$end值，然后使用strtr進行替換：

$str = 'This thing should output _$this_key$_ and also _$this_one$_ so that I can match it with an array!';
$replacements = [
    'this_key' => 'love',
    'this_one' => 'more love'
];
$start = '_$';
$end = '$_';
$replacements = array_combine(array_map(function ($v) use ($start, $end) { return "$start$v$end"; }, array_keys($replacements)), $replacements);
echo strtr($str, $replacements);

輸出：

This thing should output love and also more love so that I can match it with an array!

3v4l.org 上的演示

如果由於每次都必須重新生成$replacements數組而導致性能問題，則此循環要快得多：

foreach ($replacements as $key => $value) {
    $new_reps["_\$$key\$_"] = $value;
}

3v4l.org 上的性能比較演示

Answer 2

您可以使用preg_replace_callback ：

<?php

$str = 'This thing should output _$this_key$_ and also _$this_one$_ so that I can match it with an array!';

$replacements = [
    'this_key' => 'love',
    'this_one' => 'more love'
];

$replaced = preg_replace_callback('/_\$([^$]+)\$_/', function($matches) use ($replacements) {
    return $replacements[$matches[1]];
}, $str);

print $replaced;

你在這里有一個演示。

正則表達式，解釋：

_              # Literal '_'
\$             # Literal '$' ($ needs to be scaped as it means end of line/string)
(              # Begin of first capturing group
    [^$]+      # One carcter that cannot be "$", repeated 1 or more times
)              # End of first capturing group
\$             # Literal '$'
_              # Literal '_'

對於每個匹配項，匹配數據 ( $mathces ) 將傳遞給函數。

在數組的第一個元素上有第一個捕獲組，我們用它來進行替換。

Answer 3

希望這能解決您對問題的回答！

$items['this_key'] = 'love';
$items['this_one'] = 'more love';

$string = 'This thing should output _$this_key$_ and also _$this_one$_ so that I can match it with an array!';

$this_key = $items['this_key'];
$this_one = $items['this_one'];
$string = str_replace('_$this_key$_',$this_key,$string);
$string = str_replace('_$this_one$_',$this_one,$string);

echo  $string;