Summary of examples of commonly used array functions in PHP
The examples in this article summarize the commonly used array functions in PHP. Share it with everyone for your reference, as follows:
1. array array_merge(array $array1 [, array $array2 [, $array]])
Function function: Merge one or more The elements of the arrays are combined, and the values in one array are appended to the previous array. Returns an array of results.
If the input array has the same string key name, the value after the key name will overwrite the previous value. However, if the array contains numeric keys, the subsequent values will not overwrite the original values but will be appended to them.
If only an array is given and the array is numerically indexed, the key names are re-indexed in a consecutive manner.
Example 1: There are the same string key names in the array
$array1=array('color'=>'greed','3'=>8); $array2=array("a",'color'=>"red",'3'=>8); var_dump(array_merge($array1,$array2));
Output:
array(4){ ["color"]=> string(3) "red" [0]=> int(8) [1]=> string(1) "a" [2]=> int(8) }
The color with repeated key names is overwritten, and only the subsequent value 'red' is taken, while the '3' with the same numerical key name is not overwritten, but appended to the end.
2. array array_slice(array $array,int $offset, [, int $length [, bool $preserve_keys ]])
Function function: Return the value specified by the offset and length parameters A sequence in the array array.
If offset is non-negative: the array will start from the offset from the beginning to offset. $array=array(1,2,3,4,5,6); array_slice($array,2); equivalent to (1,2,3,4,5,6); red represents the intercepted array
If offset is negative: the array will start at the offset from the end to offset. array_slice($array,-2); Equivalent to (1,2,3,4,5,6);
If length is positive: the number of interceptions starting from offset. array_slice($array,2,2); Equivalent to (1,2,3,4,5,6);
If length is negative: the sequence will terminate this far from the end of the array; array_slice($array,2,-1); Equivalent to (1,2,3,4,5,6);
The default is: to the end of the array.
3. array_map(callback $callback, array $arr1[, array $.....])
Function function: Return an array that contains all units in arr1 The unit after callback function. The number of arguments accepted by callback should match the number of arrays passed to the array_map() function.
<?php function cube($n) { return($n * $n * $n); } $a = array(1, 2, 3, 4, 5); $b = array_map("cube", $a); print_r($b); ?>
Output:
Array ( [0] => 1 [1] => 8 [2] => 27 [3] => 64 [4] => 125 )
I hope this article will be helpful to everyone in PHP programming.
For more articles related to summaries of common PHP array function examples, please pay attention to the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











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,

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.

In PHP, exception handling is achieved through the try, catch, finally, and throw keywords. 1) The try block surrounds the code that may throw exceptions; 2) The catch block handles exceptions; 3) Finally block ensures that the code is always executed; 4) throw is used to manually throw exceptions. These mechanisms help improve the robustness and maintainability of your code.

There are four main error types in PHP: 1.Notice: the slightest, will not interrupt the program, such as accessing undefined variables; 2. Warning: serious than Notice, will not terminate the program, such as containing no files; 3. FatalError: the most serious, will terminate the program, such as calling no function; 4. ParseError: syntax error, will prevent the program from being executed, such as forgetting to add the end tag.

In PHP, the difference between include, require, include_once, require_once is: 1) include generates a warning and continues to execute, 2) require generates a fatal error and stops execution, 3) include_once and require_once prevent repeated inclusions. The choice of these functions depends on the importance of the file and whether it is necessary to prevent duplicate inclusion. Rational use can improve the readability and maintainability of the code.

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

HTTP request methods include GET, POST, PUT and DELETE, which are used to obtain, submit, update and delete resources respectively. 1. The GET method is used to obtain resources and is suitable for read operations. 2. The POST method is used to submit data and is often used to create new resources. 3. The PUT method is used to update resources and is suitable for complete updates. 4. The DELETE method is used to delete resources and is suitable for deletion operations.
