How to merge arrays and retain key values in php
Below I will share with you an implementation method of merging arrays and retaining key values in PHP. It has a good reference value and I hope it will be helpful to everyone.
php merges arrays, generally using the array_merge method.
array_merge — Merge one or more arrays
array array_merge ( array $array1 [, array $... ] )
array_merge Merge the cells of one or more arrays, the values in an array Appends to the previous array, returning the resulting array.
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 latter will not overwrite the original value, but will be appended to it.
If only an array is given and the array is numerically indexed, the key names are re-indexed in a consecutive manner.
Example 1, the array uses a string key name, the same key name will be overwritten by the subsequent one
<?php $arr1 = array('name'=>'fdipzone'); $arr2 = array('name'=>'terry'); $result = array_merge($arr1, $arr2); print_r($result); ?>
Output:
Array ( [name] => terry )
Example 2, the array uses numeric key names, the same key names will not be overwritten, and Key names will be re-indexed
<?php $arr1 = array(0=>'fdipzone',1=>'terry'); $arr2 = array(0=>'php',1=>'python'); $result = array_merge($arr1, $arr2); print_r($result); ?>
Output:
Array ( [0] => fdipzone [1] => terry [2] => php [3] => python )
Due to work needs, the answers to the two parts of the multiple-choice questions in the questionnaire need to be merged together. The answers to each part are arrays (key=>value), the key is the question number, and the value is the answer. There is no duplication of question numbers in the two parts. .
Use array_merge to merge two parts of the answer
<?php $form_data1 = array(11=>'A',12=>'B',13=>'C',14=>'D'); $form_data2 = array(25=>'B',26=>'A',27=>'D',28=>'C'); $result = array_merge($form_data1, $form_data2); print_r($result); ?>
Output:
Array ( [0] => A [1] => B [2] => C [3] => D [4] => B [5] => A [6] => D [7] => C )
Use array_merge to merge. Because the question number (key) is a number, the key name will be re-indexed, resulting in the question number not being retained.
Method to merge arrays and keep key values:
<?php $form_data1 = array(11=>'A',12=>'B',13=>'C',14=>'D'); $form_data2 = array(25=>'B',26=>'A',27=>'D',28=>'C'); $result = $form_data1 + $form_data2; print_r($result); ?>
Output:
Array ( [11] => A [12] => B [13] => C [14] => D [25] => B [26] => A [27] => D [28] => C )
Use " " operator to merge arrays, you can retain the key values of the array, if the merged array contains For the same key value, the later key value will not overwrite the previous key value (the previous key value takes precedence).
Related recommendations:
3 PHP methods for looping through arrays list(), each() and while summary
The above is the detailed content of How to merge arrays and retain key values in php. For more information, please follow other related articles on 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
1677
14
1430
52
1333
25
1278
29
1257
24
Explain secure password hashing in PHP (e.g., password_hash, password_verify). Why not use MD5 or SHA1?
Apr 17, 2025 am 12:06 AM
In PHP, password_hash and password_verify functions should be used to implement secure password hashing, and MD5 or SHA1 should not be used. 1) password_hash generates a hash containing salt values to enhance security. 2) Password_verify verify password and ensure security by comparing hash values. 3) MD5 and SHA1 are vulnerable and lack salt values, and are not suitable for modern password security.
How does PHP type hinting work, including scalar types, return types, union types, and nullable types?
Apr 17, 2025 am 12:25 AM
PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
Choosing Between PHP and Python: A Guide
Apr 18, 2025 am 12:24 AM
PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
PHP and Python: A Deep Dive into Their History
Apr 18, 2025 am 12:25 AM
PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.
PHP and Frameworks: Modernizing the Language
Apr 18, 2025 am 12:14 AM
PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.
Why Use PHP? Advantages and Benefits Explained
Apr 16, 2025 am 12:16 AM
The core benefits of PHP include ease of learning, strong web development support, rich libraries and frameworks, high performance and scalability, cross-platform compatibility, and cost-effectiveness. 1) Easy to learn and use, suitable for beginners; 2) Good integration with web servers and supports multiple databases; 3) Have powerful frameworks such as Laravel; 4) High performance can be achieved through optimization; 5) Support multiple operating systems; 6) Open source to reduce development costs.
PHP's Impact: Web Development and Beyond
Apr 18, 2025 am 12:10 AM
PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip
