PHP Arrays

PHP Arrays – Indexed, Associative & Multidimensional

An array is a collection of data stored in a single variable, where each element is accessed using a numeric or string index. Arrays are very useful for managing collections of data like a list of names, numbers, or any other related information.

Types of Arrays in PHP

  1. Indexed Arrays: Arrays with numeric keys.
  2. Associative Arrays: Arrays with named keys.
  3. Multidimensional Arrays: Arrays containing other arrays.

1. Indexed Arrays

An indexed array uses numbers (starting from 0) as keys.

Creating an Indexed Array:

<?php
$person = array("name" => "John", "age" => 30, "city" => "New York");
echo $person["name"]; // Outputs: John
?>

Try It Now

Alternative Syntax:

<?php
$person = ["name" => "John", "age" => 30, "city" => "New York"];
echo $person["age"]; // Outputs: 30
?>

Try It Now

Adding Element:

<?php
$person["country"] = "USA";
print_r($person);
// Outputs: Array ( [name] => John [age] => 30 [city] => New York [country] => USA )
?>

Try It Now

3. Multidimensional Arrays

These are arrays that contain other arrays.

Creating a Multidimensional Array

<?php
$students = [
    ["Anaya", 20, "A"],
    ["Henry", 25, "B"],
    ["Oliver", 22, "B"],
    ["Aarush", 24, "A"]
];
echo $students[1][0]; // Outputs: Henry
?>

Try It Now

Associative Multidimensional Array

<?php
$students = [
    ["name" => "Anaya", "age" => 20, "grade" => "A"],
    ["name" => "Henry", "age" => 25, "grade" => "B"],
    ["name" => "Oliver", "age" => 25, "grade" => "B"]
];
echo $students[0]["grade"]; // Outputs: A
?>

Try It Now

Array Functions

PHP provides many built-in functions to work with arrays:

Function Description Example
count() Counts the elements in an array count($array)
array_push() Adds one or more elements to the end of an array array_push($array, "Mango")
array_pop() Removes the last element of an array array_pop($array)
array_merge() Merges two or more arrays array_merge($arr1, $arr2)
in_array() Checks if a value exists in an array in_array("Apple", $fruits)
array_keys() Returns all the keys of an array array_keys($person)
array_values() Returns all the values of an array array_values($person)

Example:

<?php
$colors = ["Red", "Green", "Blue"];
echo count($colors); // Outputs: 3
?>

Try It Now

Looping Through Arrays

1. Indexed Array with for
<?php
$fruits = ["Apple", "Banana", "Mango"];
for ($i = 0; $i < count($fruits); $i++) {
    echo $fruits[$i] . "\n";
}
?>

Try It Now

2. Associative Array with foreach
<?php
$person = ["name" => "James", "age" => 25];
foreach ($person as $key => $value) {
    echo "$key: $value\n";
}
// Outputs:
// name: James
// age: 25
?>

Try It Now

Summary

  • Indexed arrays use numbers as keys.
  • Associative arrays use named keys.
  • Multidimensional arrays contain other arrays.
  • Use PHP’s built-in array functions to make working with arrays easier.