PHP traversal and search for strings-PHP Tutorial-php.cn

PHP traversal and search for strings

墨辰丷

Release： 2023-03-31 08:04:01

Original

3207 people have browsed it

本篇文章主要介绍php针对字符串的遍历与查找，感兴趣的朋友参考下，希望对大家有所帮助。

本文实例讲述了PHP函数实现从一个文本字符串中提取关键字的方法，具体分析如下：

这是一个函数定位接收一个字符串作为参数（连同其他配置可选参数），并且定位该字符串中的所有关键字（出现最多的词），返回一个数组或一个字符串由逗号分隔的关键字。功能正常工作，但我正在改进，因此，感兴趣的朋友可以提出改进意见。

/**
 * Finds all of the keywords (words that appear most) on param $str 
 * and return them in order of most occurrences to less occurrences.
 * @param string $str The string to search for the keywords.
 * @param int $minWordLen[optional] The minimun length (number of chars) of a word to be considered a keyword.
 * @param int $minWordOccurrences[optional] The minimun number of times a word has to appear 
 * on param $str to be considered a keyword.
 * @param boolean $asArray[optional] Specifies if the function returns a string with the 
 * keywords separated by a comma ($asArray = false) or a keywords array ($asArray = true).
 * @return mixed A string with keywords separated with commas if param $asArray is true, 
 * an array with the keywords otherwise.
 */
function extract_keywords($str, $minWordLen = 3, $minWordOccurrences = 2, $asArray = false)
{
  function keyword_count_sort($first, $sec)
  {
    return $sec[1] - $first[1];
  }
  $str = preg_replace(&#39;/[^\\w0-9 ]/&#39;, &#39; &#39;, $str);
  $str = trim(preg_replace(&#39;/\s+/&#39;, &#39; &#39;, $str));
  $words = explode(&#39; &#39;, $str);
  $keywords = array();
  while(($c_word = array_shift($words)) !== null)
  {
    if(strlen($c_word) <= $minWordLen) continue;
    $c_word = strtolower($c_word);
    if(array_key_exists($c_word, $keywords)) $keywords[$c_word][1]++;
    else $keywords[$c_word] = array($c_word, 1);
  }
  usort($keywords, &#39;keyword_count_sort&#39;);
  $final_keywords = array();
  foreach($keywords as $keyword_det)
  {
    if($keyword_det[1] < $minWordOccurrences) break;
    array_push($final_keywords, $keyword_det[0]);
  }
  return $asArray ? $final_keywords : implode(&#39;, &#39;, $final_keywords);
}
//How to use
//Basic lorem ipsum text to extract the keywords
$text = "
Lorem ipsum dolor sit amet, consectetur adipiscing elit. 
Curabitur eget ipsum ut lorem laoreet porta a non libero. 
Vivamus in tortor metus. Suspendisse potenti. Curabitur 
metus nisi, adipiscing eget placerat suscipit, suscipit 
vitae felis. Integer eu odio enim, sed dignissim lorem. 
In fringilla molestie justo, vitae varius risus lacinia ac. 
Nulla porttitor justo a lectus iaculis ut vestibulum magna 
egestas. Ut sed purus et nibh cursus fringilla at id purus.
";
//Echoes: lorem, suscipit, metus, fringilla, purus, justo, eget, vitae, ipsum, curabitur, adipiscing
echo extract_keywords($text);

Copy after login

总结：以上就是本篇文的全部内容，希望能对大家的学习有所帮助。

相关推荐：

php基于cookie实现换肤的方法

php针对日期操作与流程控制的方法

php实现网页缓存的工具类的代码及使用方法

The above is the detailed content of PHP traversal and search for strings. For more information, please follow other related articles on the PHP Chinese website!