PHP Indexed Arrays

An indexed array is an array where each item has a numeric index. By default, the index starts at 0 and increases by one for each subsequent item.

1. Accessing Indexed Arrays

To access an element, you use square brackets with the index number of the item you want.

<?php
    $cars = ["Volvo", "BMW", "Toyota"];
    echo $cars[0]; // Outputs: Volvo
    echo $cars[1]; // Outputs: BMW
?>

2. Modifying Elements

You can change the value of an existing element by assigning a new value to its specific index.

<?php
    $cars = ["Volvo", "BMW", "Toyota"];
    $cars[1] = "Ford"; // Overwrites BMW with Ford
    
    echo $cars[1]; // Outputs: Ford
?>

3. Looping through Indexed Arrays

To print all the values of an indexed array, you can use a for loop (using the length of the array) or a foreach loop.

Using foreach (Recommended)

<?php
    $cars = ["Volvo", "BMW", "Toyota"];
    foreach ($cars as $car) {
        echo "$car <br>";
    }
?>

4. Adding New Elements

You can add a new item to the end of an indexed array using empty square brackets []. PHP will automatically assign the next available numeric index.

<?php
    $cars = ["Volvo", "BMW"];
    $cars[] = "Toyota"; // Adds to index 2
    
    print_r($cars);
?>

Key Points to Remember

• Indexed arrays use numbers as keys, starting from 0.
• Use brackets [index] to read or write specific items.
• The foreach loop is the most efficient way to iterate through these lists.
• Append items easily using $array[] = value.
• Mixing data types inside an indexed array is possible but usually not recommended for clean code.