SMALL EXERCISES. REAL FEEDBACK.

Practice lab

Try an idea, run the checks, and understand the result.

JAVASCRIPT EXERCISE

Make a title worth saving

Return a trimmed string. Reject non-string values, blank titles, and titles longer than 120 UTF-16 code units after trimming by throwing an Error.

Your function

normalizeTitle

What the tests check

Trims surrounding spaces
Rejects whitespace-only input
Accepts 120 code units
Rejects 121 code units
Rejects non-string input

Read the related lesson

Runs JavaScript in an isolated browser worker with a 2-second limit. No terminal commands or coding agents are run. These checks are practice, not the final assessor suite.

normalizeTitle.js

function normalizeTitle(title) {
  // Normalize the value and validate it before returning.
  return title;
}

Run your code to see what passes and what needs work.

⌘ / Ctrl + Enter also runs checks.

AI Coding &Agent Operator

Practice lab

AI Coding &
Agent Operator