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Updated: May 31, 2026

String Concatenation

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Conclusion

String Concatenation — free browser-based JavaScript practice

■ What this exercise teaches Concatenate firstName and lastName and output "Yamada Taro" with console.log.

Why it matters in real projects

The + operator joins strings together. Similar patterns appear daily in code review and production UI work.

Step-by-step workflow

1. Read the guide and understand the goal of "String Concatenation" 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: Yamada, Taro. 6. After success, continue with adjacent exercises in the same category

Core concept explained

The + operator joins strings together.

Technical focus

Key JavaScript APIs: console.log.

Hint before you peek at the solution

firstName + ' ' + lastName or a template literal.

Sample solution walkthrough

JavaScript APIs used: console.log. Verify spelling and async/await usage. Explanation: The + operator joins strings together. Hint recap: firstName + ' ' + lastName or a template literal.

Solution code

📝 Sample code

const firstName = 'Yamada';
const lastName = 'Taro';
console.log(firstName + ' ' + lastName);

Common mistakes for this exact task

- Skipping the hint: firstName + ' ' + lastName or a template literal.

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: Yamada, Taro. 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 "String Concatenation" 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 String concatenation, js-basic, elementary, console.log, string concatenation—search-friendly guide for String Concatenation.

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■ Exercise task

Concatenate firstName and lastName and output "Yamada Taro" with console.log.

Hint if stuck

firstName + ' ' + lastName or a template literal.

10pt

String concatenation

Concatenate firstName and lastName and output "Yamada Taro" with console.log.

Code

const firstName = 'Yamada';
const lastName = 'Taro';

Preview

Errors & Console

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

Roadmap · All guides

Deep dive

"String Concatenation" is a elementary-level JavaScript exercise. Concatenate firstName and lastName and output "Yamada Taro" with console.log. Run it in-browser with automatic checking.

The + operator joins strings together. Similar patterns appear daily in code review and production UI work.

Pair this with the js-basic roadmap. Exercise #53 reinforces core js-basic skills.

Step-by-step workflow

Read the guide and understand the goal of "String Concatenation"
Review the JavaScript editor pane and start from the starter code
Open hints if stuck; compare your diff with the sample solution
Click Run and inspect preview/console output
Auto-check looks for output containing: Yamada, Taro.
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: The + operator joins strings together. Hint recap: firstName + ' ' + lastName or a template literal.

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: firstName + ' ' + lastName or a template literal.
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: Yamada, Taro. 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 "String Concatenation" 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 String concatenation, js-basic, elementary, console.log, string concatenation—search-friendly guide for String Concatenation.

Related dev tools

Learning roadmap

Learning roadmap →

Related exercises

Frequently asked questions

Is "String concatenation" free?

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

Difficulty and time?

"String concatenation" is level "elementary". 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 "String concatenation"?

The + operator joins strings together. Hint: firstName + ' ' + lastName or a template literal.

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 "String Concatenation"?

1. Read the guide and understand the goal of "String Concatenation" 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: Yamada, Taro. 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: The + operator joins strings together. Hint recap: firstName + ' ' + lastName or a template literal.

Something is not working?

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: Yamada, Taro. 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.

Career / interview angle?

Explain the techniques in "String Concatenation" 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?

10pt is a difficulty hint, not a score you must maximize.