PHP array deep copy method showdown: speed, memory usage and reliability

Comparison of PHP deep copy methods: Speed: clone is the fastest, followed by json_encode() json_decode(). Memory usage: json_encode() json_decode() is the least, serialize() unserialize() is the most. Reliability: All methods ensure that the original array is not affected by modifications to the copy.

PHP array deep copy method showdown: speed, memory usage and reliability

Introduction
Deep copying is crucial when dealing with multi-dimensional arrays in PHP. It creates a true copy of the array and is useful when you need to modify elements in the copy without affecting the original array. This article will compare four popular PHP deep copy methods:

Method

• ##clone
• array_map(clone, $array)
• serialize() unserialize()
• json_encode() json_decode()

Practical caseFor comparison, we create a multi-dimensional array containing 1,000 elements:

$array = range(1, 1000);
$array[] = ['a', 'b', 'c'];
$array[] = ['x' => 1, 'y' => 2];

Speed ​​testUse
microtime() to time the execution time of each method:

$time = microtime(true);
$cloneCopy = clone $array;
$microtime = microtime(true) - $time;

$time = microtime(true);
$arrayMapCloneCopy = array_map(clone, $array);
$microtime2 = microtime(true) - $time;

$time = microtime(true);
$serializeCloneCopy = unserialize(serialize($array));
$microtime3 = microtime(true) - $time;

$time = microtime(true);
$jsonCloneCopy = json_decode(json_encode($array), true);
$microtime4 = microtime(true) - $time;

Result:

Method Time (seconds)##clonearray_map(clone, $array)serialize() unserialize()##json_encode() json_decode()##Memory usage testUse

##8.9e-6
2.1e-5
8.1e-5
4.7e-5

memory_get_usage()

Measure the memory usage of each method:

$memory = memory_get_usage();
$cloneCopy = clone $array;
$memory2 = memory_get_usage() - $memory;

$memory = memory_get_usage();
$arrayMapCloneCopy = array_map(clone, $array);
$memory3 = memory_get_usage() - $memory;

$memory = memory_get_usage();
$serializeCloneCopy = unserialize(serialize($array));
$memory4 = memory_get_usage() - $memory;

$memory = memory_get_usage();
$jsonCloneCopy = json_decode(json_encode($array), true);
$memory5 = memory_get_usage() - $memory;

Result:

Method

Memory usage (bytes)##clone56,000##88,000##112,000Reliability testing

	array_map(clone, $array)
	serialize() unserialize()
##json_encode() json_decode()	64,000
	Reliability testing ensures that the original array remains unchanged when the copy is modified : $cloneCopy[0] = 100; $arrayMapCloneCopy[0] = 100; $serializeCloneCopy[0] = 100; $jsonCloneCopy[0] = 100; echo $array[0]; // 输出：1 assert($array[0] == 1); The above is the detailed content of PHP array deep copy method showdown: speed, memory usage and reliability. 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 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 AI Hentai Generator Generate AI Hentai for free. Show More Hot Article R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal) 3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌 R.E.P.O. Best Graphic Settings 3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌 Assassin's Creed Shadows: Seashell Riddle Solution 1 weeks ago By DDD R.E.P.O. How to Fix Audio if You Can't Hear Anyone 3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌 Where to find the Crane Control Keycard in Atomfall 1 weeks ago By DDD Show More 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) Show More Hot Topics Where is the login entrance for gmail email? 7442 15 CakePHP Tutorial 1371 52 What is the format of the account name of steam 76 11 win11 activation key permanent 36 19 nyt connections hints and answers 8 6 Show More Related knowledge PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati How to fine-tune deepseek locally Feb 19, 2025 pm 05:21 PM Local fine-tuning of DeepSeek class models faces the challenge of insufficient computing resources and expertise. To address these challenges, the following strategies can be adopted: Model quantization: convert model parameters into low-precision integers, reducing memory footprint. Use smaller models: Select a pretrained model with smaller parameters for easier local fine-tuning. Data selection and preprocessing: Select high-quality data and perform appropriate preprocessing to avoid poor data quality affecting model effectiveness. Batch training: For large data sets, load data in batches for training to avoid memory overflow. Acceleration with GPU: Use independent graphics cards to accelerate the training process and shorten the training time. CakePHP Date and Time Sep 10, 2024 pm 05:27 PM To work with date and time in cakephp4, we are going to make use of the available FrozenTime class. CakePHP File upload Sep 10, 2024 pm 05:27 PM To work on file upload we are going to use the form helper. Here, is an example for file upload. Discuss CakePHP Sep 10, 2024 pm 05:28 PM CakePHP is an open-source framework for PHP. It is intended to make developing, deploying and maintaining applications much easier. CakePHP is based on a MVC-like architecture that is both powerful and easy to grasp. Models, Views, and Controllers gu How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c CakePHP Quick Guide Sep 10, 2024 pm 05:27 PM CakePHP is an open source MVC framework. It makes developing, deploying and maintaining applications much easier. CakePHP has a number of libraries to reduce the overload of most common tasks. How do you parse and process HTML/XML in PHP? Feb 07, 2025 am 11:57 AM This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an See all articles Public welfare online PHP training，Help PHP learners grow quickly！ About us Disclaimer Sitemap © php.cn All rights reserved