PHP
Displaying the post list
Walk the posts array with foreach and display each post.
Walking an array with foreach
To hold several posts in one variable you use an array. With $posts = [new Post(...), new Post(...)]; you put two posts in the same array. Then foreach ($posts as $post) { ... } walks all elements in order and runs the loop body for each.
At each step the $post variable holds the current Post instance. So you can print each post's data with accesses like $post->title or $post->author. This pattern appears in every app that produces list output.
Summary output with the summary method
You add a summary(): string method to the Post class. It joins the title and author with $this->title . " - " . $this->author and returns a single string. So you don't repeat the same concatenation every time you print a post.
To call the method you write echo $post->summary();. The output looks like First post - Ayşe. The method reduces code repetition and lets you manage the post format from one place.
Exercise Add the summary method and a posts array
Add a public function summary(): string method to the Post class. Inside it write return $this->title . " - " . $this->author;. Then create a $posts array and add new Post("First post", "Hello world", "Ayşe") and new Post("Second post", "PHP is nice", "Alex"). Walk with foreach ($posts as $post) and print echo $post->summary() . "\n"; for each.
Show example solution
string { return $this->title . " - " . $this->author; } to the Post class. Write $posts = [ new Post("First post", "Hello world", "Ayşe"), new Post("Second post", "PHP is nice", "Alex"), ];. Print with foreach ($posts as $post) { echo $post->summary() . "\n"; }.
Example solution:
<?php
// Put several posts in an array and print with summary
class Post {
public string $title = "";
public string $content = "";
public string $author = "";
public function __construct(string $title, string $content, string $author) {
$this->title = $title;
$this->content = $content;
$this->author = $author;
}
public function summary(): string {
return $this->title . " - " . $this->author;
}
}
$posts = [
new Post("First post", "Hello world", "Ayşe"),
new Post("Second post", "PHP is nice", "Alex"),
];
foreach ($posts as $post) {
echo $post->summary() . "\n";
}
Test yourself
-
What does a foreach loop do?
- Only increments numbers by one
- Defines a class
- Reads a file
- Walks through all elements of an array in order
Show answer
Walks through all elements of an array in order — Correct. foreach walks all elements of an array in order and runs the loop body for each.
-
Complete the element part of the foreach loop
foreach ($posts as ____) {
echo $post->summary() . "\n";
}
Show answer
foreach ($posts as $post) {
echo $post->summary() . "\n";
}
-
Match the loop and array concepts
- foreach
- Loop construct
- $posts
- Posts array
- as $post
- Loop variable
- summary()
- Summary method
Next lesson: Project final - Blog
