How PHP outputs all variables/constants/modules/functions/class codes

PHP output Examples of all variables, constants, modules, functions, and classes of the current process

1. Get_defined_vars (PHP 4 >= 4.0.4, PHP 5)-Gets an array of all defined variables
Array get_defined_vars (void)
This function returns a multidimensional array that contains a list of all defined variables, including environment variables, server variables, and user-defined variables.

<?phpecho ' <pre> '; $b = array (1,1,2,3,5,8); $arr = Get_defined_vars ();//Print $bprint _r ($arr ["B"]);// Print all server variables Print_r ($arr ["_server"]);//print variable array of all available key values Print_r (Array_keys (Get_defined_vars ()));? >

2. Get_defined_functions (PHP 4 >= 4.0.4, PHP 5)-Get all defined functions
Array get_defined_functions (void)//void is empty and does not require any arguments

<?phpecho ' <pre> '; function foo () {    echo "This is my function foo";} $arr = Get_defined_functions ();p rint_r ($arr);? >

3. Get_loaded_extensions (PHP 4, PHP 5)-Get all available modules

<?phpecho ' <pre> ';p rint_r (Get_loaded_extensions ());? >

4. Get_extension_funcs (PHP 4, PHP 5)-Get the available functions for the specified module
Array Get_extension_funcs (string $module _name) This function returns all available functions for the specified module. The parameter passed in (module name) must be lowercase

<?phpecho ' <pre> ';p rint_r (Get_extension_funcs ("GD"));p Rint_r (Get_extension_funcs ("xml"));? >

5. Get_defined_constants (PHP 4 >= 4.1.0, PHP 5)-Gets the name of the associative array all constants and their value
Array get_defined_constants ([bool $categorize = false])

<?phpecho ' <pre> ';d efine ("My_constant", 1);p Rint_r (Get_defined_constants (true));? >

6. Get_declared_classes (PHP 4, PHP 5)-Gets an array of the names of the defined classes
Array get_declared_classes (void)

<?phpecho ' <pre> ';//define classoneclass classone {}//define Classtwoclass Classtwo {}//this'll show X classes (built-ins, extensions etc) With//classone and classtwo as the last T Wo Elementsprint_r (get_declared_classes ());//define classthreeclass classthree {}//...and fourclass classfour {}// Shows the same result as before with class three and four Appendedprint_r (Get_declared_classes ());?