PHP
Challenge - Mini API
Build a simple task tracking API with classes, JSON and DateTime.
Challenge - Mini API
In this last challenge you'll build a simple task tracking API. The Task class stores a title, a done flag and a creation time; its summarize() method turns them into a one-line report.
The creation time uses the DateTime class; format("Y-m-d H:i") produces a custom date string. A task is an object, a collection is an associative array. This combines your class, DateTime and array knowledge.
Task class skeleton
The Task class holds three private properties: private string $title, private bool $done = false, private DateTime $createdAt. The constructor takes the title and DateTime; $done defaults to false.
The markDone() method sets $this->done = true. The summarize(): string method returns the task in the form "[x] Title (2026-01-15 10:00)"; an unfinished task shows a space inside the brackets. The $this->createdAt->format("Y-m-d H:i") call formats the date.
Exercise Write the Task class and summarize method
Define a Task class with private string $title, private bool $done = false, private DateTime $createdAt. The constructor takes string $title and DateTime $createdAt. The markDone(): void method sets $this->done = true. The summarize(): string method starts with "[x] " when $this->done is true and "[ ] " otherwise; it then appends $this->title and " (" . $this->createdAt->format("Y-m-d H:i") . ")". Add the call $t = new Task("Fix login bug", new DateTime("2026-01-15 10:00")); $t->markDone(); echo $t->summarize() . "\n";.
Show example solution
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Example solution:
<?php
// Write the Task class and summarize method
class Task {
private string $title;
private bool $done = false;
private DateTime $createdAt;
public function __construct(string $title, DateTime $createdAt) {
$this->title = $title;
$this->createdAt = $createdAt;
}
public function markDone(): void {
$this->done = true;
}
public function summarize(): string {
$mark = $this->done ? "[x]" : "[ ]";
return $mark . " " . $this->title . " (" . $this->createdAt->format("Y-m-d H:i") . ")";
}
}
$t = new Task("Fix login bug", new DateTime("2026-01-15 10:00"));
$t->markDone();
echo $t->summarize() . "\n";
Test yourself
-
What does format('Y-m-d') return for new DateTime('2026-01-15 10:00')?
- 15-01-2026
- 2026-01-15
- 10:00
- 2026-01-15 10:00
Show answer
2026-01-15 — Correct. Y gives the year, m the zero-padded month, d the zero-padded day; the result is '2026-01-15'.
-
Complete the format call
$date = $this->createdAt->format(____);
Show answer
$date = $this->createdAt->format("Y-m-d H:i");
-
Match each function to its job
- new DateTime
- creates date object
- format
- formats date as string
- markDone
- marks task done
- summarize
- produces report
Next lesson: Intermediate section exam
