如何获得两个字符[字符串]之间的字符串？ PHP

Question

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

如何获得以下结果？

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 
     ) 

) 

而这里的rregex的解释：

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

Answer 2

对于那些警惕正则表达式，这里有一个解决方案SANS那个疯狂的正则表达式语法。 :-)它曾经真的激怒了我这样的事情是不是原产于PHP的字符串函数，所以我建一个...

// 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; 
} 

当然，这可以浓缩了不少。为了节省别人清除它的努力：

// 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)); 
}