search
HomeBackend DevelopmentPHP ProblemHow to use php associative array

PHP is a very powerful programming language that supports many data types, one of which is associative arrays. Unlike ordinary arrays, associative arrays are one-to-one key-value pairs, and any type of value can be used as the key name of the array, not just numbers. In PHP development, associative arrays are a very commonly used data type. This article will introduce the basic usage of associative arrays.

  1. Create an associative array

To create an associative array, just use the array() function. The following is a simple example:

$info = array(
    'name' => '张三',
    'age' => 24,
    'sex' => '男'
);

The above code creates an associative array named $info, which contains three key-value pairs, namely 'name', 'age' and 'sex'. The value of 'name' is the string 'Zhang San', the value of 'age' is the number 24, and the value of 'sex' is the string 'male'.

  1. Accessing associative arrays

The method of accessing associative arrays is similar to that of ordinary arrays, you only need to use the key name. The following is a simple example:

echo $info['name']; // 输出:张三
echo $info['age']; // 输出:24
echo $info['sex']; // 输出:男

As you can see, when using an associative array to access elements, you only need to use the key name. The advantage of this is that it can make the code clearer and easier to read.

  1. Traversing associative arrays

The method of traversing associative arrays is similar to that of ordinary arrays, and can be implemented using a foreach loop. The following is a simple example:

foreach($info as $key => $value) {
    echo "键名:{$key},键值:{$value}<br/>";
}

The above code uses a foreach loop to traverse the $info array, where $key represents the key name and $value represents the key value. In the loop body, the contents of each key name and key value are output.

  1. Modify the associative array

The method of modifying the associative array is also very simple, just use the key name. The following is a simple example:

$info['name'] = '李四';
$info['age'] = 25;
$info['sex'] = '女';

The above code modifies the values ​​of $name, $age and $sex respectively, changing them to '李思', 25 and 'Female' respectively.

  1. Delete associative array elements

The method of deleting associative array elements is also very simple, just use the unset() function. The following is a simple example:

unset($info['sex']);

The above code deletes the 'sex' key-value pair in the $info array.

In short, associative arrays are one of the data types often used in PHP programming. Proficiency in their basic usage is very important for developing PHP programs. This article introduces the basic operation methods of creating, accessing, traversing, modifying and deleting associative arrays. It is a very useful reference for beginners.

The above is the detailed content of How to use php associative array. For more information, please follow other related articles on the PHP Chinese website!

Statement
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
What are the best practices for deduplication of PHP arraysWhat are the best practices for deduplication of PHP arraysMar 03, 2025 pm 04:41 PM

This article explores efficient PHP array deduplication. It compares built-in functions like array_unique() with custom hashmap approaches, highlighting performance trade-offs based on array size and data type. The optimal method depends on profili

Does PHP array deduplication need to be considered for performance losses?Does PHP array deduplication need to be considered for performance losses?Mar 03, 2025 pm 04:47 PM

This article analyzes PHP array deduplication, highlighting performance bottlenecks of naive approaches (O(n²)). It explores efficient alternatives using array_unique() with custom functions, SplObjectStorage, and HashSet implementations, achieving

Can PHP array deduplication take advantage of key name uniqueness?Can PHP array deduplication take advantage of key name uniqueness?Mar 03, 2025 pm 04:51 PM

This article explores PHP array deduplication using key uniqueness. While not a direct duplicate removal method, leveraging key uniqueness allows for creating a new array with unique values by mapping values to keys, overwriting duplicates. This ap

How to Implement message queues (RabbitMQ, Redis) in PHP?How to Implement message queues (RabbitMQ, Redis) in PHP?Mar 10, 2025 pm 06:15 PM

This article details implementing message queues in PHP using RabbitMQ and Redis. It compares their architectures (AMQP vs. in-memory), features, and reliability mechanisms (confirmations, transactions, persistence). Best practices for design, error

What Are the Latest PHP Coding Standards and Best Practices?What Are the Latest PHP Coding Standards and Best Practices?Mar 10, 2025 pm 06:16 PM

This article examines current PHP coding standards and best practices, focusing on PSR recommendations (PSR-1, PSR-2, PSR-4, PSR-12). It emphasizes improving code readability and maintainability through consistent styling, meaningful naming, and eff

What are the optimization techniques for deduplication of PHP arraysWhat are the optimization techniques for deduplication of PHP arraysMar 03, 2025 pm 04:50 PM

This article explores optimizing PHP array deduplication for large datasets. It examines techniques like array_unique(), array_flip(), SplObjectStorage, and pre-sorting, comparing their efficiency. For massive datasets, it suggests chunking, datab

How Do I Work with PHP Extensions and PECL?How Do I Work with PHP Extensions and PECL?Mar 10, 2025 pm 06:12 PM

This article details installing and troubleshooting PHP extensions, focusing on PECL. It covers installation steps (finding, downloading/compiling, enabling, restarting the server), troubleshooting techniques (checking logs, verifying installation,

How to Use Reflection to Analyze and Manipulate PHP Code?How to Use Reflection to Analyze and Manipulate PHP Code?Mar 10, 2025 pm 06:12 PM

This article explains PHP's Reflection API, enabling runtime inspection and manipulation of classes, methods, and properties. It details common use cases (documentation generation, ORMs, dependency injection) and cautions against performance overhea

See all articles

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

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

DVWA

DVWA

Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.