PHP Indexed Arrays (Step-by-Step Guide with Examples)
PHP Indexed Arrays are arrays with numeric indexes that start from 0 by default. These arrays allow you to store multiple values under a single variable, making it easier to manage related data.
1. What is an Indexed Array?
An indexed array in PHP is an array where each element is assigned a numeric index starting from 0.
Example: Creating an Indexed Array
<?php
$fruits = ["Apple", "Banana", "Cherry"];
echo $fruits[0]; // Output: Apple
?>
2. Creating an Indexed Array
Method 1: Using Square Brackets ([])
<?php
$colors = ["Red", "Green", "Blue"];
?>
Method 2: Using array() Function
<?php
$colors = array("Red", "Green", "Blue");
?>
3. Accessing Elements in an Indexed Array
You can access elements using their index. The first element starts at index 0.
<?php
$colors = ["Red", "Green", "Blue"];
echo $colors[1]; // Output: Green
?>
4. Adding Elements to an Indexed Array
Adding Elements Manually
<?php
$colors = ["Red", "Green"];
$colors[] = "Blue"; // Adds "Blue" to the array
print_r($colors);
?>
Using array_push()
<?php
$colors = ["Red", "Green"];
array_push($colors, "Blue", "Yellow"); // Adds multiple elements
print_r($colors);
?>
5. Modifying Elements in an Indexed Array
You can change an element by accessing it via its index.
<?php
$colors = ["Red", "Green", "Blue"];
$colors[1] = "Yellow"; // Changes "Green" to "Yellow"
print_r($colors);
?>
6. Removing Elements from an Indexed Array
Using unset() (Removes a Specific Element)
<?php
$colors = ["Red", "Green", "Blue"];
unset($colors[1]); // Removes "Green"
print_r($colors);
?>
💡 Note: The indexes will not reset automatically.
Using array_splice() (Reindexes Automatically)
<?php
$colors = ["Red", "Green", "Blue"];
array_splice($colors, 1, 1); // Removes "Green" and shifts elements
print_r($colors);
?>
7. Looping Through an Indexed Array
Using for Loop
<?php
$colors = ["Red", "Green", "Blue"];
for ($i = 0; $i < count($colors); $i++) {
echo $colors[$i] . "<br>";
}
?>
8. Sorting Indexed Arrays
Sorting in Ascending Order (sort())
<?php
$numbers = [4, 2, 8, 1];
sort($numbers);
print_r($numbers); // Output: [1, 2, 4, 8]
?>
Sorting in Descending Order (rsort())
<?php
$numbers = [4, 2, 8, 1];
rsort($numbers);
print_r($numbers); // Output: [8, 4, 2, 1]
?>
9. Useful PHP Array Functions
| Function | Description | Example |
|---|---|---|
count() | Returns number of elements | count($arr) |
array_push() | Adds element to the end | array_push($arr, "PHP") |
array_pop() | Removes last element | array_pop($arr) |
array_merge() | Merges two arrays | array_merge($arr1, $arr2) |
in_array() | Checks if a value exists | in_array("PHP", $arr) |
array_values() | Gets all values from an array | array_values($arr) |
sort() | Sorts an array in ascending order | sort($arr) |
rsort() | Sorts an array in descending order | rsort($arr) |
10. Converting Indexed Arrays to Strings
Convert Array to String (Implode)
<?php
$colors = ["Red", "Blue", "Green"];
echo implode(", ", $colors); // Output: Red, Blue, Green
?>
Convert String to Array (Explode)
<?php
$text = "PHP, JavaScript, Python";
$languages = explode(", ", $text);
print_r($languages);
?>
