Arrays (Indexed, Associative, Multidimensional)

 

Introduction

An array in PHP is a data structure that stores multiple values in a single variable. Arrays make it easy to work with lists of data without creating separate variables for each item. PHP supports three main types of arrays: Indexed, Associative, and Multidimensional.

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Indexed Arrays

Indexed arrays store values with numeric indexes starting from 0. They are useful when you only need to access values by their position.

Example:

<?php
$colors = ["Red", "Green", "Blue"];

echo $colors[0]; // Outputs: Red
echo $colors[1]; // Outputs: Green
echo $colors[2]; // Outputs: Blue
?>

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Associative Arrays

Associative arrays use named keys instead of numeric indexes. They are helpful when you want to access elements by a meaningful name rather than a number.

Example:

<?php
$person = [
    "name" => "John",
    "age" => 30,
    "city" => "Dubai"
];

echo $person["name"]; // Outputs: John
echo $person["city"]; // Outputs: Dubai
?>

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Multidimensional Arrays

Multidimensional arrays are arrays that contain other arrays. They are useful for representing complex data structures, such as tables or nested information.

Example:

<?php
$students = [
    ["John", 20, "A"],
    ["Sara", 22, "B"],
    ["Mike", 19, "A+"]
];

echo $students[0][0]; // Outputs: John
echo $students[1][2]; // Outputs: B
?>

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Using print_r to Display Arrays

The print_r() function is useful for quickly displaying the structure and contents of an array, especially while debugging.

Example:

<?php
$fruits = ["Apple", "Banana", "Cherry"];

print_r($fruits);
?>

Output:

Array
(
    [0] => Apple
    [1] => Banana
    [2] => Cherry
)

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Looping Through Arrays

You can use the foreach loop to iterate through arrays easily.

Example:

<?php
$fruits = ["Apple", "Banana", "Cherry"];

foreach ($fruits as $fruit) {
    echo $fruit . "\n";
}
?>

Output:

Apple
Banana
Cherry