Some less common features of PHP

Some of the less common features of PHP 1. variable function name. you can concatenate the function name functionaa ($ str) {echo $ str;} $ function = "aa"; $ function ('Hello '); // or php features that are not commonly used
1. variable function name, which can be concatenated with a string

function aa($str) {  echo $str;}$function = "aa";$function('Hello');// ORcall_user_func($function, $param);

2. list all functions and determine whether a function exists.

get_defined_functions()function_exist()

3. accept PUT requests, essential for PHP REST

parse_str(file_get_contents('php://input'), $put_vars);

4. parse time from string

echo date('Y-m-d', strtotime('-1 month ago'));

5. View and call backtrace in DEBUG

$backtrace = debug_backtrace();var_export($backtrace[0])die();

6. interactive command line, command line execution PHP

Php-a and php-r 'echo "hello ";'

For more information, see php-h.

7. memory usage detection

memory_get_peak_usage()memory_get_usage()