php - 2文字間の文字列を取得するにはどうすればよいですか[文字列]？PHP

Question

$string1 = "This is test [example]";
$string2 = "This is test [example][2]";
$string3 = "This [is] test [example][3]";

次の結果を得るにはどうすればよいですか？

For $string1 -> example
For $string2 -> example*2
For $string3 -> is*example*3

Answer 1

preg_match_all('/\[([^\]]+)\]/', $str, $matches);

php > preg_match_all('/\[([^\]]+)\]/', 'This [is] test [example][3]', $matches);
php > print_r($matches);
Array
(
    [0] => Array
        (
            [0] => [is]
            [1] => [example]
            [2] => [3]
        )

    [1] => Array
        (
            [0] => is
            [1] => example
            [2] => 3
        )

)

そして、これがrregexの説明です：

\[ # literal [
( # group start
    [^\]]+ # one or more non-] characters
) # group end
\] # literal ]

Answer 2

正規表現に警戒している人のために、ここにそのクレイジーな正規表現構文がない解決策があります。:-)これは、このようなものがPHPの文字列関数にネイティブではないことを本当に苛立たせていたので、私はそれを作成しました...

// Grabs the text between two identifying substrings in a string. If $Echo, it will output verbose feedback.
function BetweenString($InputString, $StartStr, $EndStr=0, $StartLoc=0, $Echo=0) {
    if (!is_string($InputString)) { if ($Echo) { echo "<p>html_tools.php BetweenString() FAILED. \$InputString is not a string.</p>\n"; } return; }
    if (($StartLoc = strpos($InputString, $StartStr, $StartLoc)) === false) { if ($Echo) { echo "<p>html_tools.php BetweenString() FAILED. Could not find \$StartStr '{$StartStr}' within \$InputString |{$InputString}| starting from \$StartLoc ({$StartLoc}).</p>\n"; } return; }
    $StartLoc += strlen($StartStr);
    if (!$EndStr) { $EndStr = $StartStr; }
    if (!$EndLoc = strpos($InputString, $EndStr, $StartLoc)) { if ($Echo) { echo "<p>html_tools.php BetweenString() FAILED. Could not find \$EndStr '{$EndStr}' within \$InputString |{$InputString}| starting from \$StartLoc ({$StartLoc}).</p>\n"; } return; }
    $BetweenString = substr($InputString, $StartLoc, ($EndLoc-$StartLoc));
    if ($Echo) { echo "<p>html_tools.php BetweenString() Returning |'{$BetweenString}'| as found between \$StartLoc ({$StartLoc}) and \$EndLoc ({$EndLoc}).</p>\n"; }
    return $BetweenString; 
}

もちろん、これはかなり凝縮することができます。他の誰かをクリーンアップする手間を省くために：

// Grabs the text between two identifying substrings in a string.
function BetweenStr($InputString, $StartStr, $EndStr=0, $StartLoc=0) {
    if (($StartLoc = strpos($InputString, $StartStr, $StartLoc)) === false) { return; }
    $StartLoc += strlen($StartStr);
    if (!$EndStr) { $EndStr = $StartStr; }
    if (!$EndLoc = strpos($InputString, $EndStr, $StartLoc)) { return; }
    return substr($InputString, $StartLoc, ($EndLoc-$StartLoc));
}