In-depth study of available methods for PHP checking functions-PHP Tutorial

In-depth study on the methods available for PHP checks. We are using PHP to check function availability 1. get all available modules-get_loaded_extensions this function returns all loaded (available) modules. Usage: print_r (get_loade we are using

PHP check function availability 1. get all available modules-get_loaded_extensions
This function returns all loaded (available) modules.

Usage:

Print_r (get_loaded_extensions ());

PHP check function available 2. get the available function of the specified module-get_extension_funcs
This function returns all available functions of the specified module. The input parameter (module name) must be in lowercase.

Usage:

Print_r (get_extension_funcs ("gd "));

PHP check function available 3. get all defined functions-get_defined_functions
This function returns all defined functions, including built-in functions and user-defined functions.

Usage:

 
 

  
  
function myrow($id, $data){ 
  
  
return "$id$datan"; 
  
  
} 
  
  
$arr = get_defined_functions(); 
  
  
print_r($arr); 
 
 

Output:

 
 

  
  
Array 
  
  
( 
  
  
[internal] => Array 
  
  
( 
  
  
[0] => zend_version 
  
  
[1] => func_num_args 
  
  
[2] => func_get_arg 
  
  
[3] => func_get_args 
  
  
[4] => strlen 
  
  
[5] => strcmp 
  
  
[6] => strncmp 
  
  
... 
  
  
[750] => bcscale 
  
  
[751] => bccomp 
  
  
) 
  
  
[user] => Array 
  
  
( 
  
  
[0] => myrow 
  
  
) 
  
  
) 
 
 

$ Arr ["internal"] is a built-in function, and $ arr ["user"] is a user-defined function.

PHP check function availability 4. check whether the specified function exists-function_exists

This function returns whether the specified function has been defined.

Usage:

 
 

  
  
if (function_exists('imap_open')) { 
  
  
echo "IMAP functions are available.
n"; 
  
  
} else { 
  
  
echo "IMAP functions are not available.
n"; 
 
 

PHP checks whether the function is available. 1. obtain all available modules-get_loaded_extensions. This function returns all loaded (available) modules. Usage: print_r (get_loade...