Adding Elements to an Array

Part of the Fundamentals section of Coddy's PHP journey — lesson 39 of 71.

You've learned how to modify existing elements, but what about adding new elements to an array? PHP makes this simple with the empty bracket syntax.

To add an element to the end of an array, use empty square brackets on the left side of an assignment:

<?php
$fruits = ["Apple", "Banana"];

$fruits[] = "Cherry";
$fruits[] = "Date";

echo count($fruits); // 4
?>

Each time you use $array[] = value, PHP automatically assigns the next available index. In the example above, "Cherry" gets index 2 and "Date" gets index 3.

This is particularly useful when you start with an empty array and build it up over time:

<?php
$shoppingList = [];

$shoppingList[] = "Milk";
$shoppingList[] = "Bread";
$shoppingList[] = "Eggs";

echo $shoppingList[0]; // Milk
echo $shoppingList[2]; // Eggs
?>

The empty bracket syntax always appends to the end of the array, so you don't need to calculate or track the next index yourself. PHP handles it automatically.

Challenge

Easy

Read a line of input containing comma-separated values representing initial items in a list (e.g., Apple,Banana).

Then read three more inputs:

A string item1 to add to the array
A string item2 to add to the array
A string item3 to add to the array

Create an array from the comma-separated input, then add the three new items to the end of the array using the empty bracket syntax.

Print the following on separate lines:

The total count of items in the array after adding all three
The element at index 2
The last element of the array (use count() to find the last index)

Example:

If the inputs are Apple,Banana, Cherry, Date, and Elderberry, the output should be:

5
Cherry
Elderberry

If the inputs are Red,Blue,Green, Yellow, Purple, and Orange, the output should be:

6
Green
Orange

Cheat sheet

To add elements to the end of an array, use empty square brackets [] on the left side of an assignment:

<?php
$fruits = ["Apple", "Banana"];

$fruits[] = "Cherry";
$fruits[] = "Date";

echo count($fruits); // 4
?>

PHP automatically assigns the next available index each time you use $array[] = value.

This works with empty arrays too:

<?php
$shoppingList = [];

$shoppingList[] = "Milk";
$shoppingList[] = "Bread";
$shoppingList[] = "Eggs";

echo $shoppingList[0]; // Milk
echo $shoppingList[2]; // Eggs
?>

To access the last element of an array, use count($array) - 1 as the index:

<?php
$items = ["A", "B", "C"];
echo $items[count($items) - 1]; // C
?>

Try it yourself

<?php
// Read the comma-separated initial items
$input = trim(fgets(STDIN));
$items = explode(',', $input);

// Read the three items to add
$item1 = trim(fgets(STDIN));
$item2 = trim(fgets(STDIN));
$item3 = trim(fgets(STDIN));

// TODO: Write your code below
// Add the three items to the array using empty bracket syntax
// Then print:
// 1. The total count of items
// 2. The element at index 2
// 3. The last element (use count() to find the last index)

?>

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Adding Elements to an Array

Cheat sheet

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