PHP Arrays
Store multiple values in a single variable
📚 What are PHP Arrays?
Arrays are a fundamental data structure in PHP that allow you to store multiple values in a single variable. Instead of creating separate variables for each value, you can group related values together in an array. This makes your code more organized and efficient, especially when working with lists of data.
<?php
// Simple array example
$fruits = array("Apple", "Banana", "Orange");
echo $fruits[0]; // Apple
echo $fruits[1]; // Banana
?>
Output:
Apple
Banana
Types of Arrays
Indexed Arrays
Arrays with numeric indexes starting from 0. Perfect for ordered lists where position matters, like rankings or sequences.
<?php
$colors = ["Red", "Green", "Blue"];
echo $colors[0]; // Red
?>Associative Arrays
Arrays with named keys instead of numbers. Use descriptive keys to access values, making code more readable and self-documenting.
<?php
$person = ["name" => "John", "age" => 25];
echo $person["name"]; // John
?>Multidimensional Arrays
Arrays containing other arrays. Create complex data structures like tables, matrices, or nested lists for organizing hierarchical information.
<?php
$students = [
["Alice", 20],
["Bob", 22]
];
?>Array Functions
PHP provides powerful built-in functions to manipulate arrays. Sort, search, filter, merge, and transform arrays with ease using these tools.
<?php
$nums = [3, 1, 2];
sort($nums);
print_r($nums); // [1, 2, 3]
?>🔹 Creating Indexed Arrays
Indexed arrays are created using numeric indexes (starting from 0) to store multiple values in a single variable. This is useful when you have a collection of items where the order matters, such as a list of fruits or vegetables.
<?php
// Method 1: Using array() function
$fruits = array("Apple", "Banana", "Orange");
// Method 2: Using short syntax []
$vegetables = ["Carrot", "Potato", "Tomato"];
// Accessing elements
echo "First fruit: " . $fruits[0];
echo "<br>";
echo "Second vegetable: " . $vegetables[1];
?>Output:
First fruit: Apple
Second vegetable: Potato
🔹 Associative Arrays
Use named keys to access array values:
<?php
// Create associative array
$student = array(
"name" => "Alice",
"age" => 20,
"grade" => "A"
);
// Access values using keys
echo "Name: " . $student["name"];
echo "<br>";
echo "Age: " . $student["age"];
echo "<br>";
echo "Grade: " . $student["grade"];
?>Output:
Name: Alice
Age: 20
Grade: A
🔹 Looping Through Arrays
Looping through arrays allows you to access and process each element individually. PHP provides two main ways to loop through arrays: using a for loop or a foreach loop.
<?php
$colors = ["Red", "Green", "Blue", "Yellow"];
// Using for loop
echo "Using for loop:<br>";
for($i = 0; $i < count($colors); $i++) {
echo $colors[$i] . "<br>";
}
echo "<br>Using foreach loop:<br>";
// Using foreach loop (easier)
foreach($colors as $color) {
echo $color . "<br>";
}
?>Output:
Using for loop:
Red
Green
Blue
Yellow
Using foreach loop:
Red
Green
Blue
Yellow
🔹 Looping Associative Arrays
To process associative arrays, you can loop through them and access both the key (name) and value for each element. This is useful when you want to display or work with both the property names and their corresponding values.
<?php
$person = [
"name" => "John",
"age" => 25,
"city" => "New York"
];
foreach($person as $key => $value) {
echo "$key: $value<br>";
}
?>Output:
name: John
age: 25
city: New York
🔹 Multidimensional Arrays
Arrays containing other arrays:
<?php
$students = [
["Alice", 20, "A"],
["Bob", 22, "B"],
["Charlie", 21, "A"]
];
// Access elements
echo "First student: " . $students[0][0];
echo "<br>";
echo "Bob's grade: " . $students[1][2];
echo "<br><br>All students:<br>";
foreach($students as $student) {
echo $student[0] . " (Age: " . $student[1] . ", Grade: " . $student[2] . ")<br>";
}
?>Output:
First student: Alice
Bob's grade: B
All students:
Alice (Age: 20, Grade: A)
Bob (Age: 22, Grade: B)
Charlie (Age: 21, Grade: A)
🔹 Common Array Functions
PHP provides many useful array functions:
<?php
$numbers = [3, 1, 4, 1, 5, 9, 2];
// Count elements
echo "Count: " . count($numbers);
echo "<br>";
// Sort array
sort($numbers);
echo "Sorted: " . implode(", ", $numbers);
echo "<br>";
// Add element to end
array_push($numbers, 10);
echo "After push: " . implode(", ", $numbers);
echo "<br>";
// Check if value exists
if(in_array(5, $numbers)) {
echo "5 is in the array";
}
?>Output:
Count: 7
Sorted: 1, 1, 2, 3, 4, 5, 9
After push: 1, 1, 2, 3, 4, 5, 9, 10
5 is in the array
🔹 Array Manipulation
Add, remove, and modify array elements:
<?php
$fruits = ["Apple", "Banana"];
// Add to end
$fruits[] = "Orange";
echo "Added Orange: " . implode(", ", $fruits);
echo "<br>";
// Remove last element
array_pop($fruits);
echo "After pop: " . implode(", ", $fruits);
echo "<br>";
// Add to beginning
array_unshift($fruits, "Mango");
echo "Added Mango at start: " . implode(", ", $fruits);
echo "<br>";
// Remove first element
array_shift($fruits);
echo "After shift: " . implode(", ", $fruits);
?>Output:
Added Orange: Apple, Banana, Orange
After pop: Apple, Banana
Added Mango at start: Mango, Apple, Banana
After shift: Apple, Banana
🔹 Practical Example
Create a simple shopping cart using arrays:
<?php
$cart = [
["name" => "Laptop", "price" => 999, "qty" => 1],
["name" => "Mouse", "price" => 25, "qty" => 2],
["name" => "Keyboard", "price" => 75, "qty" => 1]
];
$total = 0;
echo "Shopping Cart:<br><br>";
foreach($cart as $item) {
$subtotal = $item["price"] * $item["qty"];
$total += $subtotal;
echo $item["name"] . " - $" . $item["price"] . " × " . $item["qty"] . " = $" . $subtotal . "<br>";
}
echo "<br><strong>Total: $" . $total . "</strong>";
?>Output:
Shopping Cart:
Laptop - $999 × 1 = $999
Mouse - $25 × 2 = $50
Keyboard - $75 × 1 = $75
Total: $1124
💡 Array Tips:
- Use foreach: Easiest way to loop through arrays
- count(): Get the number of elements in an array
- in_array(): Check if a value exists in an array
- implode(): Convert array to string
- explode(): Convert string to array