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Array

An array in PHP is a variable that holds more than one value at a time, and you can access each value using its position or a name.

Array Types

In PHP, arrays are mainly of three types. Arrays are used to store multiple values in a single variable in different ways.

1. Indexed Array

An indexed array stores values with numeric indexes (0, 1, 2, …).

2. Associative Array

An associative array stores values using named keys (like names instead of numbers).

3. Multidimensional Array

A multidimensional array is an array that contains another array inside it.

Indexed Array

An indexed array in PHP is a type of array where each element is stored in a specific position called an index number.

The index always starts from 0, so:

First element → index 0
Second element → index 1
Third element → index 2, and so on

This means every value in the array is accessed using its number position.

Example

// Creating an indexed array of cars
$cars = array("Volvo", "BMW", "Toyota");

// Changing the value at index 1 (BMW is replaced with Ford)
$cars[1] = "Ford";

// var_dump() is used to display full details of the array
var_dump($cars);
?>

Associative Array

An associative array is an array that stores data in key-value pairs, where each value is accessed by a custom name (key) instead of a numeric index.

Example

$person = [
"name" => "Rahul",
"age" => 25,
"city" => "Bhopal"
];

echo $person["name"];
echo $person["age"];
echo $person["city"];
?>

Create Array

You can create arrays in different ways depending on how you want to store data.

1. Using array() Function

2. Using Short Syntax (Preferred Method)

3. Creating Associative Array

4. Creating Empty Array

5. Mixing Array Keys

Example

// 1. Using array() Function
$array1 = array("Apple", "Banana", "Mango");
// Old traditional way of creating an indexed array

// 2. Using Short Syntax (Preferred Method)
$array2 = ["Red", "Green", "Blue"];
// Modern and recommended way (short syntax)

// 3. Creating Associative Array
$array3 = [
"name" => "John",
"age" => 25,
"city" => "Delhi"
];
// Key => Value pairs (useful for structured data)

// 4. Creating Empty Array
$array4 = [];
// Empty array, can add elements later

// Adding values to empty array
$array4[] = "First Value";
$array4[] = "Second Value";

// 5. Mixing Array Keys
$array5 = [
0 => "Zero Index",
"fruit" => "Apple",
1 => "One Index",
"color" => "Red"
];
// Mix of numeric and associative keys

// Output all arrays using print_r for readability

echo "Array 1:\n";
print_r($array1);

echo "\nArray 2:\n";
print_r($array2);

echo "\nArray 3 (Associative):\n";
print_r($array3);

echo "\nArray 4 (Empty then filled):\n";
print_r($array4);

echo "\nArray 5 (Mixed Keys):\n";
print_r($array5);

?>

Sorting Arrays

In PHP, sorting arrays is easy because there are built-in functions that do the work for you.
But different functions are used depending on the type of array:

Indexed Array → normal list (0, 1, 2…)
Associative Array → key-value pairs (name => "John")

Array Sorting Functions

sort() - sorts an indexed array in ascending order
rsort() - sorts an indexed array in descending order
asort() - sorts an associative array in ascending order, according to the value
ksort() - sorts an associative array in ascending order, according to the key
arsort() - sorts an associative array in descending order, according to the value
krsort() - sorts an associative array in descending order, according to the key

Example

// Indexed Array Example

$numbers = [5, 2, 9, 1];

// sort() → Ascending order (small to big)
sort($numbers);
echo "\nsort() - Ascending Order:\n";
print_r($numbers);

// rsort() → Descending order (big to small)
rsort($numbers);
echo "\nrsort() - Descending Order:\n";
print_r($numbers);

// Associative Array Example

$data = [
"b" => "Banana",
"a" => "Apple",
"c" => "Cherry"
];

echo "\nOriginal Associative Array:\n";
print_r($data);

// asort() → Sort by values (A to Z), keep keys
asort($data);
echo "\nasort() - Sort by VALUE (Ascending):\n";
print_r($data);

// arsort() → Sort by values (Z to A), keep keys
arsort($data);
echo "\narsort() - Sort by VALUE (Descending):\n";
print_r($data);

// ksort() → Sort by keys (A to Z)
ksort($data);
echo "\nksort() - Sort by KEY (Ascending):\n";
print_r($data);

// krsort() → Sort by keys (Z to A)
krsort($data);
echo "\nkrsort() - Sort by KEY (Descending):\n";
print_r($data);

?>

Remove Array Items

Removing array items in PHP means deleting one or more elements from an array using built-in functions.

Removing / Deleting Array Items in PHP Using Different Functions

array_splice() - removes a portion of the array starting from a start position and length
unset() - removes the element associated with a specific key
array_diff() - remove items from an associative array
array_pop() - removes the last array item
array_shift() - removes the first array item

Example

// ======================
// Original Array
// ======================

$fruits = ["Apple", "Banana", "Mango", "Orange", "Grapes"];

echo "Original Array:\n";
print_r($fruits);

// =====================================
// 1. array_splice()
// Removes part of array using start position & length
// =====================================

$temp1 = $fruits; // Copy original array
array_splice($temp1, 1, 2);
// Removes 2 elements starting from index 1 ("Banana", "Mango")

echo "\nAfter array_splice() (remove from index 1, length 2):\n";
print_r($temp1);

// =====================================
// 2. unset()
// Removes element using specific key (index)
// =====================================

$temp2 = $fruits;
unset($temp2[2]);
// Removes element at index 2 ("Mango")

echo "\nAfter unset() (remove index 2):\n";
print_r($temp2);

// =====================================
// 3. array_diff()
// Removes specific values from array
// =====================================

$temp3 = $fruits;
$result = array_diff($temp3, ["Banana", "Grapes"]);
// Removes "Banana" and "Grapes"

echo "\nAfter array_diff() (remove Banana & Grapes):\n";
print_r($result);

// =====================================
// 4. array_pop()
// Removes last element of array
// =====================================

$temp4 = $fruits;
array_pop($temp4);
// Removes last element ("Grapes")

echo "\nAfter array_pop() (remove last item):\n";
print_r($temp4);

// =====================================
// 5. array_shift()
// Removes first element of array
// =====================================

$temp5 = $fruits;
array_shift($temp5);
// Removes first element ("Apple")

echo "\nAfter array_shift() (remove first item):\n";
print_r($temp5);

?>

Array Functions

Function	Use
array()	Creates an array
range()	Creates an array with a range of values
count()	Counts number of elements in array
array_push()	Adds elements at the end of array
array_pop()	Removes last element
array_shift()	Removes first element
array_unshift()	Adds elements at the beginning
unset()	Removes specific element by key/index
array_splice()	Removes or replaces part of array
in_array()	Checks if a value exists in array
array_search()	Finds key of a value
array_keys()	Returns all keys
array_values()	Returns all values
array_merge()	Combines multiple arrays
array_unique()	Removes duplicate values
array_reverse()	Reverses array order
sort()	Sorts array in ascending order
rsort()	Sorts array in descending order
asort()	Sorts associative array by value (ASC)
arsort()	Sorts associative array by value (DESC)
ksort()	Sorts associative array by key (ASC)
krsort()	Sorts associative array by key (DESC)
array_sum()	Returns sum of values
array_product()	Returns product of values
array_filter()	Filters array elements
array_map()	Applies function to each element