dongxia026531 2019-03-30 09:17
浏览 125

不同的模式但结果是一样的

I want to get the input values in the string. I use two different patterns for this. But the result is the same. What is the reason of this?

$string = 'hello world is .. <input type="text" id="level" value="5">  <input type="text" id="option" value="24"> .. tyhis is example text.';

$pattern = '/<input(?:.*?)id=\"option\"(?:.*)value=\"([^"]+).*>/i';
$pattern2 = '/<input(?:.*?)id=\"level\"(?:.*)value=\"([^"]+).*>/i';

preg_match($pattern, $string, $matches);
preg_match($pattern2, $string, $matches2);
echo $matches[1];
echo "<br>";
echo $matches2[1];

Result:

24

24

What is the reason of this?

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1条回答 默认 最新

  • douguan1887 2019-03-30 09:48
    关注

    As @Andreas already stated your patterns contain greedy sections which swallow too much of the input. You need to reduce that:

    <?php
    $string = 'hello world is .. <input type="text" id="level" value="5">  <input type="text" id="option" value="24"> .. this is example text.';
    
    $pattern1 = '/<input\s.*\sid=\"option\"\s.*?value=\"([^"]+).*>/i';
    $pattern2 = '/<input\s.*\sid=\"level\"\s.*?value=\"([^"]+).*>/i';
    
    
    preg_match($pattern1, $string, $matches1);
    preg_match($pattern2, $string, $matches2);
    
    var_dump($matches1[1], $matches2[1]);
    

    The obvious output is:

    string(2) "24"
    string(1) "5"
    
    评论

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