How to get information about a function in PHP?

Methods to get function information in PHP: get_defined_functions(): Returns the names of all defined functions, classified by internal, user and merged lists. get_function_arg(): Returns the argument list of a specific function. get_function_args(): Returns arguments as strings. Reflection API: Get more details about a function such as name, file name, documentation comments through reflection objects.

How to get information about functions in PHP

PHP provides a variety of functions that allow you to get information about runtime functions. information. This article explores these functions so you can effectively understand and manipulate your code.

get_defined_functions()

This function returns an array containing the names of all defined functions. It is divided into three parts:

• #internal: Contains the names of PHP built-in functions.
• user: Contains the name of the user-defined function.
• all: Contains a merged list of internal and user-defined functions.

Example:

$functions = get_defined_functions();
print_r($functions['internal']);

get_function_arg()

This function returns the argument list of a specific function.

Example:

$args = get_function_arg('array_sum');
print_r($args);

get_function_args()

This function is similar to get_function_arg(), But the parameters will be returned as strings.

Example:

$args = get_function_args('array_sum');
echo $args;

reflection

The Reflection API allows you to access more about a function by creating a function reflection object details.

Example:

$reflection = new ReflectionFunction('array_sum');
echo $reflection->getName();
echo $reflection->getFileName();
echo $reflection->getDocComment();

Actual case:

// 获取所有已定义函数的名称
$functions = get_defined_functions();
echo "All defined functions:";
print_r($functions['all']);

// 获取特定函数的参数
$args = get_function_arg('array_sum');
echo "Parameters of array_sum:";
print_r($args);

// 获取反射对象以获取函数元数据
$reflection = new ReflectionFunction('array_sum');
echo "Function name:" . $reflection->getName();
echo "File name:" . $reflection->getFileName();

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