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Updated: May 31, 2026

Define Function

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Conclusion

Define Function — free browser-based JavaScript practice

■ What this exercise teaches Define a function called greet that returns "Hello".

Why it matters in real projects

function defines a function and return sends back its value. Similar patterns appear daily in code review and production UI work.

Step-by-step workflow

1. Read the guide and understand the goal of "Define Function" 2. Review the JavaScript editor pane and start from the starter code 3. Open hints if stuck; compare your diff with the sample solution 4. Click Run and inspect preview/console output 5. Auto-check looks for output containing: Hello. 6. After success, continue with adjacent exercises in the same category

Core concept explained

function defines a function and return sends back its value.

Technical focus

Key JavaScript APIs: console.log.

Hint before you peek at the solution

function greet() { return 'Hello'; }

Sample solution walkthrough

JavaScript APIs used: console.log. Verify spelling and async/await usage. Explanation: function defines a function and return sends back its value. Hint recap: function greet() { return 'Hello'; }

Solution code

📝 Sample code
function greet() {
  return 'Hello';
}
console.log(greet());

Common mistakes for this exact task

- Skipping the hint: function greet() { return 'Hello'; }

Troubleshooting

Q: Preview does not change after Run A: Ensure you edited the JavaScript pane and clicked Run. Q: Looks correct but check fails A: Auto-check looks for output containing: Hello. Look for typos, full-width spaces, or unclosed tags. Q: Console shows errors A: Open DevTools Console and fix bracket/quote mismatches at the reported line. Q: Hard to type on mobile A: Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Interview / portfolio tips

- Explain the techniques in "Define Function" in your own words within 30 seconds - Practice walking through each line of the sample solution on a whiteboard - Connect this task to a real component you would ship - Mention responsive or accessibility trade-offs - Describe when you use: console.log

What to do after you pass

Move to the next exercise in the js-basic track, then continue the learning roadmap at /en/learning/js-basic/.

Keywords

Free hands-on exercise covering Define a function, js-basic, beginner, console.log, define function—search-friendly guide for Define Function.

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■ Exercise task

Define a function called greet that returns "Hello".

Hint if stuck

function greet() { return 'Hello'; }

15pt

Define a function

Define a function called greet that returns "Hello".

Click error to highlight line. ✕=error ⚠=warning ›=log.

Roadmap · All guides

Deep dive

"Define Function" is a beginner-level JavaScript exercise. Define a function called greet that returns "Hello". Run it in-browser with automatic checking.

function defines a function and return sends back its value. Similar patterns appear daily in code review and production UI work.

Pair this with the js-basic roadmap. Exercise #23 reinforces core js-basic skills.

Step-by-step workflow

  1. Read the guide and understand the goal of "Define Function"
  2. Review the JavaScript editor pane and start from the starter code
  3. Open hints if stuck; compare your diff with the sample solution
  4. Click Run and inspect preview/console output
  5. Auto-check looks for output containing: Hello.
  6. After success, continue with adjacent exercises in the same category

How to read the sample solution

JavaScript APIs used: console.log. Verify spelling and async/await usage. Explanation: function defines a function and return sends back its value. Hint recap: function greet() { return 'Hello'; }

Real-world & career relevance

JS basics precede React, Vue, and Node. Variables, functions, and arrays appear in daily code review.

Common mistakes

  • Skipping the hint: function greet() { return 'Hello'; }
  • Typos in console.log
  • Loose == between string and number
  • Reassigning const
  • Missing semicolons causing odd line breaks

Troubleshooting

Preview does not change after Run
Ensure you edited the JavaScript pane and clicked Run.
Looks correct but check fails
Auto-check looks for output containing: Hello. Look for typos, full-width spaces, or unclosed tags.
Console shows errors
Open DevTools Console and fix bracket/quote mismatches at the reported line.
Hard to type on mobile
Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Interview & portfolio tips

  • Explain the techniques in "Define Function" in your own words within 30 seconds
  • Practice walking through each line of the sample solution on a whiteboard
  • Connect this task to a real component you would ship
  • Mention responsive or accessibility trade-offs
  • Describe when you use: console.log

Glossary

const
Constant binding—no reassignment.
function
Reusable block of code.
console.log
Print to the developer console.

Keywords covered on this page

Free hands-on exercise covering Define a function, js-basic, beginner, console.log, define function—search-friendly guide for Define Function.

Related dev tools

Learning roadmap

Learning roadmap →

Related exercises

Frequently asked questions

Is "Define a function" free?

This exercise is free and runs entirely in your browser. No account or credit card required.

Difficulty and time?

"Define a function" is level "beginner". Read the guide first; beginners can usually finish within 30 minutes. Allow 5–15 minutes per exercise. Use hints, then the solution if stuck.

What after a correct answer?

After a correct answer, use "Next exercise". When you finish a category, continue on the <a href="/en/learning/js-basic/">learning roadmap</a>.

Works on mobile?

Works on mobile browsers, but typing code is easier on a desktop.

Where are other exercises?

All exercises: <a href="/en/learn/">/en/learn/</a> with category filters.

Key takeaway for "Define a function"?

function defines a function and return sends back its value. Hint: function greet() { return 'Hello'; }

Where does JavaScript Basics fit?

JS basics precede React, Vue, and Node. Variables, functions, and arrays appear in daily code review.

Step-by-step for "Define Function"?

1. Read the guide and understand the goal of "Define Function"<br />2. Review the JavaScript editor pane and start from the starter code<br />3. Open hints if stuck; compare your diff with the sample solution<br />4. Click Run and inspect preview/console output<br />5. Auto-check looks for output containing: Hello.<br />6. After success, continue with adjacent exercises in the same category

How to read the sample solution?

JavaScript APIs used: console.log. Verify spelling and async/await usage.<br /><br />Explanation: function defines a function and return sends back its value.<br /><br />Hint recap: function greet() { return 'Hello'; }

Something is not working?

<strong>Preview does not change after Run</strong> → Ensure you edited the JavaScript pane and clicked Run.<br /><strong>Looks correct but check fails</strong> → Auto-check looks for output containing: Hello. Look for typos, full-width spaces, or unclosed tags.<br /><strong>Console shows errors</strong> → Open DevTools Console and fix bracket/quote mismatches at the reported line.<br /><strong>Hard to type on mobile</strong> → Use landscape mode or continue on desktop—the same URL keeps progress in localStorage.

Career / interview angle?

Explain the techniques in "Define Function" in your own words within 30 seconds Practice walking through each line of the sample solution on a whiteboard Connect this task to a real component you would ship Mention responsive or accessibility trade-offs Describe when you use: console.log

Related dev tools?

<a href="/en/tools/json-formatter/">JSON Formatter</a>, <a href="/en/tools/regex/">Regex Tester</a>

Prerequisites?

Read the <a href="/en/learning/js-basic/">Learning roadmap</a> chapter first.

Can I change the starter code?

Yes—if it works. Understanding the starter first, then adding minimal diffs, speeds up learning.

What do the points mean?

15pt is a difficulty hint, not a score you must maximize.