Home Backend Development PHP Tutorial A brief discussion of PHP source code fifteen: About the array_walk function

A brief discussion of PHP source code fifteen: About the array_walk function

Jun 28, 2018 pm 05:28 PM

This article mainly introduces the brief discussion on PHP source code 15: Regarding the array_walk function, it has a certain reference value. Now I share it with you. Friends in need can refer to it.

Brief discussion on PHP source code 10 Five: About the array_walk function

array_walk

(PHP 3 >= 3.0.3, PHP 4, PHP 5)
array_walk — Apply user function to each member of the array
Description

bool array_walk (array &array, callback funcname [, mixed userdata] )

Returns TRUE if successful and FALSE if failed.
Apply the user-defined function funcname to each cell in the array array. Typically funcname accepts two parameters. The value of the array parameter is used as the first one, and the key name is used as the second one. If the optional argument userdata is provided, it will be passed as the third argument to callback funcname.
If the funcname function requires more parameters than given, an E_WARNING level error will be generated each time array_walk() calls funcname. These warnings can be suppressed by preceding the array_walk() call with PHP's error operator @, or by using error_reporting().
Note: If funcname needs to act directly on the values ​​in the array, specify the first parameter to funcname as a reference. Thus any changes to these cells will also change the original array itself.
Note: Passing key name and userdata into funcname is new in PHP 4.0.

array_walk() is not affected by array's internal array pointer. array_walk() will walk through the entire array regardless of the position of the pointer. (This is because the program resets the pointer of the hash table where the array is located at the beginning of the array traversal)
The user should not change the array itself in the callback function. For example, add/delete units, unset units, etc. If the array that array_walk() acts on changes, the behavior of this function is undefined and unpredictable.
Program implementation description:
The last call of the extension is the function php_array_walk:

   static int php_array_walk(HashTable *target_hash, zval **userdata, int recursive TSRMLS_DC)
Copy after login

When recursive == 0, this function is the array_walk function implementation

When recursive == 1 , this function is the implementation of the array_walk_recursive function

In the source code, the program will traverse the entire array, and for each array element, make relevant function calls based on the passed in function
The function call is as follows:

fci.size = sizeof(fci);
            fci.function_table = EG(function_table);
            fci.function_name = *BG(array_walk_func_name);
            fci.symbol_table = NULL;
            fci.object_pp = NULL;
            fci.retval_ptr_ptr = &retval_ptr;
            fci.param_count = userdata ? 3 : 2;
            fci.params = args;
            fci.no_separation = 0;             /* Call the userland function */
            if (zend_call_function(&fci, &array_walk_fci_cache TSRMLS_CC) == SUCCESS) {
Copy after login

A structure is used in this function call. The comments added by me are as follows:

 typedef struct _zend_fcall_info {
 size_t size;    //    整个结构体的长度,等于sizeof(此函数体的变量)
 HashTable *function_table;    //    executor_globals.function_table
 zval *function_name;    //    函数名 
 HashTable *symbol_table;
 zval **retval_ptr_ptr;        //    函数的返回值
 zend_uint param_count;    //    参数个数
 zval ***params;            //    所调用函数的参数
 zval **object_pp;        //    用于对象的方法调用时,存储对象
 zend_bool no_separation;    //    是否清空参数所在的栈} zend_fcall_info;
Copy after login

The above are personal notes. If there are any mistakes, please correct me!

EOF

The above is the entire content of this article. I hope it will be helpful to everyone’s study. For more related content, please pay attention to the PHP Chinese website!

Related recommendations:

A brief discussion on PHP source code 14: About the array_combine function

A brief discussion on PHP source code 13: Introduction to array_change_key_case and array_chunk

A brief discussion of PHP source code 12: About return_value Return value

The above is the detailed content of A brief discussion of PHP source code fifteen: About the array_walk function. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

How does session hijacking work and how can you mitigate it in PHP? How does session hijacking work and how can you mitigate it in PHP? Apr 06, 2025 am 12:02 AM

Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.

Describe the SOLID principles and how they apply to PHP development. Describe the SOLID principles and how they apply to PHP development. Apr 03, 2025 am 12:04 AM

The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.

How to automatically set permissions of unixsocket after system restart? How to automatically set permissions of unixsocket after system restart? Mar 31, 2025 pm 11:54 PM

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

How to debug CLI mode in PHPStorm? How to debug CLI mode in PHPStorm? Apr 01, 2025 pm 02:57 PM

How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

How to send a POST request containing JSON data using PHP's cURL library? How to send a POST request containing JSON data using PHP's cURL library? Apr 01, 2025 pm 03:12 PM

Sending JSON data using PHP's cURL library In PHP development, it is often necessary to interact with external APIs. One of the common ways is to use cURL library to send POST�...

See all articles