checkmark

PHP

Introduction to PHP

What is PHP? Advantages of PHP How PHP Works (Server-Side Scripting) Setting Up a PHP Development Environment

Basics of PHP

Writing Your First PHP Script Comments in PHP Variables and Data Types Constants Operators in PHP

Control Structures

Conditional Statements (if, else, elseif) Switch Statement Loops (for, while, do-while) Break and Continue Statements

Functions in PHP

Introduction to Functions Defining Functions Function Parameters and Return Values Scope of Variables (Local and Global) Built-In Functions vs. User-Defined Functions

Arrays in PHP

Introduction to Arrays Indexed Arrays Associative Arrays Multidimensional Arrays Array Functions

Working with Forms

Creating HTML Forms Submitting Form Data Handling Form Data in PHP Form Validation and Sanitization

Working with Files and Directories

File Handling in PHP (Opening, Reading, Writing) Uploading Files in PHP Working with Directories File I/O Operations

Databases and MySQL

Setting Up a MySQL Database Connecting to a Database Querying a Database (SELECT, INSERT, UPDATE, DELETE) Prepared Statements Handling Database Errors

PHP Sessions and Cookies

Introduction to Sessions Cookies in PHP

Object-Oriented Programming (OOP)

Introduction to Object-Oriented Programming (OOP) in PHP Classes and Objects Constructors and Destructors Inheritance and Polymorphism Encapsulation and Abstraction

Error Handling and Exception Handling

Handling Errors in PHP Custom Error Handling Introduction to Exceptions Try, Catch, Finally Blocks Creating Custom Exceptions

PHP and Web Security

SQL Injection Prevention Cross-Site Scripting (XSS) Prevention Cross-Site Request Forgery (CSRF) Protection Data Validation and Sanitization Password Hashing PHP Security Checklist

PHP Frameworks and CMS

Introduction to PHP Frameworks (e.g., Laravel, Symfony) Overview of PHP Content Management Systems (e.g., WordPress, Joomla)

Advanced PHP Topics

RESTful APIs with PHP Working with JSON Data Creating Web Services Composer and Package Management Debugging PHP Code Performance Optimization Best Practices in PHP Development
menu Back to Edkool

Associative Arrays

Associative Arrays in PHP

Associative arrays are a versatile and powerful data structure in PHP. Unlike indexed arrays, where elements are identified by numeric indices, associative arrays use keys (often strings) to identify elements. This allows you to create relationships between keys and values, making associative arrays ideal for storing and organizing data in a structured manner.

Creating an Associative Array

To create an associative array in PHP, you use key-value pairs enclosed within curly braces {} or using the array() constructor. Here's an example:

$person = [
    "first_name" => "John",
    "last_name" => "Doe",
    "age" => 30
];

In this example, the $person array uses keys like "first_name," "last_name," and "age" to identify values associated with them.

Accessing Elements

To access elements within an associative array, you use their keys instead of numeric indices. For example, to access the "first_name" key:

$firstName = $person["first_name"];

Modifying Elements

You can modify elements in an associative array by assigning a new value to a specific key. For instance, to change the "age" value to 35:

$person["age"] = 35;

Counting Elements

To determine the number of elements in an associative array, you can use the count function or the sizeof function. For example:

$numberOfKeys = count($person);

Looping Through Associative Arrays

Iterating through the elements of an associative array is a common task in PHP. You can use a foreach loop to traverse the elements directly by their keys and values. Here's an example:

$person = [
    "first_name" => "John",
    "last_name" => "Doe",
    "age" => 30
];

foreach ($person as $key => $value) {
    echo "$key: $value<br>";
}

This code will output:

first_name: John
last_name: Doe
age: 30

Conclusion

Associative arrays in PHP are essential for organizing data with meaningful keys and values. They are commonly used for tasks like storing user profiles, configuration settings, or database records. By understanding how to create, access, modify, and loop through associative arrays, you can effectively manage structured data and create efficient PHP applications.

Previous Indexed Arrays
Next Multidimensional Arrays