when writing php programs, you often need to use regular expressions process text. in web development, it is necessary extract specific information from html. this article will introduce how match all form elements with the name attribute in < p>
html are core components forms, including text boxes, check radio buttons, drop-down lists, etc. applications, a identify themselves so that data can be sent server when submitted.
in php, the following steps implement this function:
step 1: obtain html content<
first, obtain content web page. you php's file_get_contents function get page content. for example, code obtains specified url: p>
$html="file_get_contents('http://www.example.com/');step 2: write expression< p>
next, write expression characters properties of element. regular character pattern-based matching tool help us p>
in attribute: >preg_match_all(' the meaning above as follows: p> with expression, value stored $matches variable. p> step 3: result processing< p> finally, results variable, output matched element screen, save database . p> for page: >foreach ($matches[1] $name) { echo $name ' complete implementation example< p> the complete sample program demonstrates use html: >< div> summary< by using expressions, we easily article, showed have attribute. through learn complex apply them actual development. p>
The above is the detailed content of PHP regular expression: How to match all form elements with name attribute in HTML. For more information, please follow other related articles on the PHP Chinese website!
[^>]*< matches any not >< (excluding newlines). li>names*="s*":" equal sign and quotation marks name< value. li>([^ "] )< matches sequence non-double quote characters, used represent values. li>[^>]*>< end >< li>< ul>
'; }< div>
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