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PHP Arrays

PHP arrays are powerful tools that allow developers to store and manage multiple values in a single variable. This is especially useful when working with large amounts of related data such as names, items, or records.

Let’s imagine you’re running a car dealership and you want to manage the stock of your cars. Instead of creating individual variables for each car, PHP allows you to group them using arrays.

Definition: An array is a special variable that can hold more than one value at a time.

Types of PHP Arrays

PHP supports three types of arrays, each useful in different scenarios.

Indexed Arrays

These arrays use numeric indexes (starting from 0) to store data in a list format.

Example:

$cars = array("Volvo", "BMW", "Toyota");
echo $cars[0]; // Outputs: Volvo

You can also create indexed arrays manually:

$cars[0] = "Volvo";
$cars[1] = "BMW";
$cars[2] = "Toyota";

Associative Arrays

These use named keys to associate values, making the data more descriptive.

Example:

$age = array("Peter" => 35, "Ben" => 37, "Joe" => 43);
echo $age["Peter"]; // Outputs: 35

You can also declare it this way:

$age["Peter"] = 35;
$age["Ben"] = 37;
$age["Joe"] = 43;

Multidimensional Arrays

These are arrays that contain other arrays as elements. They are useful for representing tables or complex data.

Example:

$cars = array(
  array("Volvo", 22, 18),
  array("BMW", 15, 13),
  array("Saab", 5, 2),
  array("Land Rover", 17, 15)
);
echo $cars[0][0]; // Outputs: Volvo
echo $cars[0][1]; // Outputs: 22

Creating Arrays in PHP

There are two ways to create arrays:

  • Using the array() function:

$fruits = array("apple", "banana", "cherry");

  • Using the short array syntax (available since PHP 5.4):

$fruits = ["apple", "banana", "cherry"];

Accessing and Modifying Array Elements

To access values:

echo $fruits[1]; // Outputs: banana
echo $age["Joe"]; // Outputs: 43

To modify values:

$fruits[1] = "mango";
$age["Joe"] = 44;

Array Length

To get the number of elements in an array, use the count() function.

Example:

$cars = array("Volvo", "BMW", "Toyota");
echo count($cars); // Outputs: 3

Looping Through Arrays

Using for Loop (for indexed arrays):

$cars = array("Volvo", "BMW", "Toyota");
for ($i = 0; $i < count($cars); $i++) {
  echo $cars[$i] . "\n";
}

Using foreach Loop (for all types):

$age = array("Peter" => 35, "Ben" => 37, "Joe" => 43);
foreach ($age as $name => $value) {
  echo "Key=$name, Value=$value\n";
}

Working with Multidimensional Arrays

You can access nested elements using multiple indices.

Example:

$cars = array(
  array("Volvo", 22, 18),
  array("BMW", 15, 13)
);

echo $cars[0][0] . ": In stock: " . $cars[0][1] . ", sold: " . $cars[0][2];

Nested Loop Example:

$cars = array(
  array("Volvo", 22, 18),
  array("BMW", 15, 13),
  array("Saab", 5, 2),
  array("Land Rover", 17, 15)
);

for ($row = 0; $row < 4; $row++) {
  echo "Row number $row\n";
  for ($col = 0; $col < 3; $col++) {
    echo $cars[$row][$col] . "\n";
  }
}

Adding and Removing Elements

Adding values:

array_push($fruits, "orange");
$person["city"] = "Delhi";

Removing values:

array_pop($fruits); // Removes last element
unset($person["age"]); // Removes key-value pair

Useful Array Functions in PHP

  • array_merge(): Combines arrays

  • in_array(): Checks if a value exists

  • sort(): Sorts values in ascending order

Example:

$a = [1, 2];
$b = [3, 4];
$result = array_merge($a, $b);
print_r($result); // Outputs: [1, 2, 3, 4]

Conclusion

Arrays are essential for efficient data handling in PHP. Whether you’re creating a shopping cart, managing user data, or processing results, arrays give you flexibility and control. Learn to choose the right type of array and master the built-in functions—they’re your toolkit for smarter coding.

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