Multidimensional Arrays

Introduction

A single array is great for a flat list of values or one record's worth of fields. But real data is often structured like a table — multiple rows, each with the same set of columns. Think of a spreadsheet of students, a list of products with prices, or search results with several fields each.

PHP handles this naturally with multidimensional arrays: arrays whose values are themselves arrays. This lesson covers how to build them, how to access and modify nested values, how to loop over them with nested foreach loops, and works through a complete example that prints a small student report.

What is a Multidimensional Array?

A multidimensional array is simply an array where each element is itself an array. This is exactly how you represent a list of records — each "row" is an associative array of fields, and the outer array holds all of the rows together.

<?php
$students = [
    ["name" => "Rahul", "grade" => 78],
    ["name" => "Priya", "grade" => 92],
    ["name" => "Aman", "grade" => 65],
];

print_r($students);
?>

Array
(
    [0] => Array
        (
            [name] => Rahul
            [grade] => 78
        )

    [1] => Array
        (
            [name] => Priya
            [grade] => 92
        )

    [2] => Array
        (
            [name] => Aman
            [grade] => 65
        )

)

Accessing Nested Values

To reach a value inside a nested array, chain the keys together: first the outer array's index (which row), then the inner array's key (which field).

<?php
$students = [
    ["name" => "Rahul", "grade" => 78],
    ["name" => "Priya", "grade" => 92],
    ["name" => "Aman", "grade" => 65],
];

echo $students[0]["name"] . "\n";
echo $students[1]["grade"] . "\n";
echo $students[2]["name"] . " scored " . $students[2]["grade"] . "\n";
?>

Rahul
92
Aman scored 65

You can nest arrays as deeply as you need — an array of arrays of arrays — though in practice most real-world data rarely goes beyond two or three levels before it makes sense to reach for objects instead.

Looping With Nested foreach

To process every value in a multidimensional array, use an outer foreach to loop over the rows, and an inner foreach (or direct key access) to loop over each row's fields.

<?php
$students = [
    ["name" => "Rahul", "grade" => 78],
    ["name" => "Priya", "grade" => 92],
];

foreach ($students as $student) {
    foreach ($student as $field => $value) {
        echo "$field: $value\n";
    }
    echo "---\n";
}
?>

name: Rahul
grade: 78
---
name: Priya
grade: 92
---

Often you already know the field names in advance, in which case you do not need a fully generic inner loop — you can just reference the known keys directly, as shown in the next example.

Worked Example: Student Report

Let's put this together into a small, complete program: a list of student records, each with a name and a grade, looped over to print a formatted report with a pass/fail label for each student.

<?php
$students = [
    ["name" => "Rahul", "grade" => 78],
    ["name" => "Priya", "grade" => 92],
    ["name" => "Aman", "grade" => 39],
    ["name" => "Sneha", "grade" => 55],
];

echo "--- Student Report ---\n";

foreach ($students as $index => $student) {
    $rowNumber = $index + 1;
    $status = $student["grade"] >= 40 ? "Pass" : "Fail";

    echo "$rowNumber. " . $student["name"] . " - " . $student["grade"] . "/100 - $status\n";
}
?>

--- Student Report ---
1. Rahul - 78/100 - Pass
2. Priya - 92/100 - Pass
3. Aman - 39/100 - Fail
4. Sneha - 55/100 - Pass

Modifying Nested Values

You can update a value deep inside a multidimensional array the same way you access it — by chaining the keys on the left side of an assignment.

<?php
$students = [
    ["name" => "Rahul", "grade" => 78],
    ["name" => "Priya", "grade" => 92],
];

// Give everyone 2 bonus points
$students[0]["grade"] += 2;
$students[1]["grade"] += 2;

foreach ($students as $student) {
    echo $student["name"] . ": " . $student["grade"] . "\n";
}
?>

Rahul: 80
Priya: 94

Common Mistakes

Best Practices

Frequently Asked Questions

Key Takeaways

Summary

Multidimensional arrays let you model structured, tabular data directly in PHP, without needing a database or external file for small, simple collections.

In this lesson, you learned what multidimensional arrays are, how to access and modify nested values, how to loop over them with nested foreach loops, and worked through a complete student-report example. Next, you will learn how to control your program's flow using conditional statements.