Detailed explanation of various examples of string processing methods in php_PHP tutorial

PHP's ability to process strings is very powerful, and its methods are diverse, but sometimes you need to choose the simplest and ideal solution. The article lists 10 common string processing cases in PHP and provides the corresponding most ideal processing methods.

1. Determine the length of a string
This is the most obvious example in the article. The question is how do we determine the length of a string? Here we cannot Not to mention is the strlen() function:

$text = "sunny day"; $count = strlen($text); // $count = 9

2. Interception Text, create a summary
News websites usually intercept a paragraph of about 200 words and add an ellipsis at the end of the sub-paragraph to form a summary. At this time, you can use the substr_replace() function to implement this function. Due to space reasons, only the 40-character limit is demonstrated here:

$article = "BREAKING NEWS: In ultimate irony, man bites dog.";

$summary = substr_replace($ article, "...", 40);

　//$summary = "BREAKING NEWS: In ultimate irony, man bi..."

　3. Calculate strings The number of characters and words in
I believe you will often see some blogs or news articles to summarize the total word count of the article, or we often see some submission requirements: within a certain word count range. At this time, you can use the str_word_count() function to calculate the total number of words in the article:

$article = "BREAKING NEWS: In ultimate irony, man bites dog.";

$wordCount = str_word_count ($article); // $wordCount = 8

Sometimes you need to more strictly control the space used by contributors, such as some comments and so on. If you want to know how many characters make up an array, use the count_chars() function.

　 4. Parse CSV files
Data is usually stored in files in comma-delimited form (such as a known CSV file). CSV files use a comma or similar Groups each column of strings into a separate row based on predefined symbols. You may often create PHP scripts to import this data, or parse out what you need. Over the years, I have seen many methods of parsing CSV files. The most common is to use a combination of fgets() and explode() functions. To read and parse the file, however, the easiest way to solve the problem is to use a function that is not part of PHP's string processing library: the fgetcsv() function. Using the fopen() and fgetcsv() functions, we can easily parse this file and retrieve the name of each contact:

　$fh = fopen("contacts.csv", "r") ;

　while($line = fgetcsv($fh, 1000, ","))

　{ echo "Contact: {$line[1]}"; }

　5. Convert to a string array
Sometimes, you may need to create CSV files and read in these files at the same time, which means you need to separate those with commas Convert the string into data. If the data was initially retrieved from a database, it would most likely only give you an array. At this time, you can use the implode() function to convert these strings into an array:

　$csv = implode(",", $record);

　6. Convert URLs into hyperlinks
Currently many WYSIWYG editors provide toolbars that allow users to mark text, including hyperlinks. However, you can easily automate this process while ensuring that you don't encounter additional errors when the content is rendered to the page. To convert a hyperlink URL, you can use the preg_replace() function, which searches a string according to a regular expression and defines the structure of the URL:

　$url = "W.J. Gilmore, LLC ( http://www.php100.com)";http://www.php100.com)"

　$url = preg_replace("/http://([A-z0-9./- ] )/", "$0", $url);

　// $url = "W.J. Gilmore, LLC (

　7. Remove HTML tags from a string
As a web developer, one of your main jobs is to ensure that user input does not contain dangerous characters. If there are, this will lead to SQL injection or script attacks. The PHP language contains many security features. Functions can help you filter data, including extended filters. For example, you can allow users to include some basic HTML statements to achieve this function, you can use the function strip_tags(). The default is to remove all HTML tags from the string, but it is also allowed to override the default or tags you specify. For example, in the following example, you can remove all tags:

　$text. = strip_tags($input, "

　");

8. Compare two strings
Compare two strings to make sure they are the same .For example, to determine whether the password entered by the user for the first time and the second time is the same, you can use the substr_compare() function to easily find out:

　$pswd = "secret";

　$ pswd2 = "secret";

　if (! strcmp($pswd, $pswd2))

　{ echo "The passwords are not identical!";

　}

If you want to determine whether two strings are case-insensitive, you can use the strcasecmp() function.

　9. Convert newlines
In this article I introduced how to easily convert the URL into a hyperlink. Now I introduce the nl2br() function, which can help you convert any Line breaks are converted into HTML tags.

　$comment = nl2br($comment);

10. Apply automatic word wrapping
To apply automatic word wrapping, you can use this function in PHP: wordwrap( )：

　$speech = "Four score and seven years ago our fathers brought forth, upon this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.";

echo wordwrap($speech, 30);

Executing the above code, the result is:

Four score and seven years ago our fathers brought forth, upon this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.

http://www.bkjia.com/PHPjc/486195.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/486195.htmlTechArticlePHP’s ability to process strings is very powerful, and there are many methods, but sometimes you need to choose one The simplest and ideal solution. The article lists 10 common strings in PHP...