PHP has a very rich built-in function, many of which we have used, but there are still many functions that most of us are not familiar with, but they are very useful. In this article, I list some little-known PHP functions that will make your eyes bright.
Have you ever experienced the time when you need to know how different two words are? This function is here to help you solve this problem. It can compare the degree of difference between two strings.
Usage:
<?php $str1 = "carrot"; $str2 = "carrrott"; echo levenshtein($str1, $str2); //Outputs 2 ?>
get_defined_vars()
This is very useful when debug debugging Useful functions. This function returns a multidimensional array, which contains all defined variables.
Usage:
<?php print_r(get_defined_vars()); ?>
php_check_syntax()
This function is very useful and can be used to check whether the syntax of PHP is correct. For technical reasons, this function has been removed starting from PHP 5.05.
Usage:
<?php $error_message = ""; $filename = "./php_script.php"; if(!php_check_syntax($filename, &$error_message)) { echo "Errors were found in the file $filename: $error_message"; } else { echo "The file $filename contained no syntax errors"; } ?>
ignore_user_abort()
This function is used to reject the browser user’s request to terminate the execution of the script. . Under normal circumstances, the client's exit will cause the server-side script to stop running.
Usage:
<?php ignore_user_abort(); ?>
highlight_string()
When you want to display PHP code on the page, ## The #highlight_string() function will be very useful. This function will highlight the PHP code you provide using the color defined by the built-in PHP syntax highlighting. This function has two parameters. The first parameter is a string, indicating that this string needs to be highlighted. If the second parameter is set to TRUE, this function will return the highlighted code as the return value.
Usage
<?php highlight_string(' <?php phpinfo(); ?>'); ?>
highlight_file
This is a very useful PHP function that can return the specified PHP file. And highlight the file content with highlight colors according to syntax and semantics. The highlighted code is processed using HTML markup.Usage:
<?php highlight_file("php_script.php"); ?>
php_strip_whitespace
This function is also similar to the previousshow_source() function Similar, but it removes comments and whitespace characters from the file.
Usage:
<?php echo php_strip_whitespace("php_script.php"); ?>
get_browser
This function will read thebrowscap.ini file, Returns browser compatibility information.
Usage:
<?php echo $_SERVER['HTTP_USER_AGENT']; $browser = get_browser(); print_r($browser); ?>
memory_get_usage(),memory_get_peak_usage(),getrusage()
These functions are used to obtain memory and CPU usage,memory_get_usage()The function returns the memory usage,
memory_get_peak_usage()The function returns the peak memory usage, getrusage() Returns CUP usage, these functions will give you some useful information when debugging PHP code performance. But please note that these functions are not valid on Windows.
Usage:
<?php echo "Initial: ".memory_get_usage()." bytes \n"; echo "Peak: ".memory_get_peak_usage()." bytes \n"; $data = getrusage(); echo "User time: ". ($data['ru_utime.tv_sec'] + $data['ru_utime.tv_usec'] / 1000000); echo "System time: ". ($data['ru_stime.tv_sec'] + $data['ru_stime.tv_usec'] / 1000000); ?>
Usage:
<?php $string = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc ut elit id mi ultricies adipiscing. Nulla facilisi. Praesent pulvinar, sapien vel feugiat vestibulum, nulla dui pretium orci, non ultricies elit lacus quis ante. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam pretium ullamcorper urna quis iaculis. Etiam ac massa sed turpis tempor luctus. Curabitur sed nibh eu elit mollis congue. Praesent ipsum diam, consectetur vitae ornare a, aliquam a nunc. In id magna pellentesque tellus posuere adipiscing. Sed non mi metus, at lacinia augue. Sed magna nisi, ornare in mollis in, mollis sed nunc. Etiam at justo in leo congue mollis. Nullam in neque eget metus hendrerit scelerisque eu non enim. Ut malesuada lacus eu nulla bibendum id euismod urna sodales. "; $compressed = gzcompress($string); $original = gzuncompress($compressed); ?>
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