PHP traversal and search for strings
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('/[^\\w0-9 ]/', ' ', $str);
$str = trim(preg_replace('/\s+/', ' ', $str));
$words = explode(' ', $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, 'keyword_count_sort');
$final_keywords = array();
foreach($keywords as $keyword_det)
{
if($keyword_det[1] < $minWordOccurrences) break;
array_push($final_keywords, $keyword_det[0]);
}
return $asArray ? $final_keywords : implode(', ', $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);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：
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!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1664
14
1423
52
1321
25
1269
29
1249
24
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
