Classic Code Challenge Solver

The code challenge solver provides an in-browser mini-IDE for editing and running assessments.

Completing a Code Challenge Quick Start

When you start a code challenge, you'll be provided some instructions and a starting point for your solution.

Once you've read the instructions, use the solution editor to code your solution. Use either the RUN TESTS or SUBMIT SOLUTION buttons to verify your code.

  • RUN TESTS will run your code against the sample tests you can edit. These will not be used for scoring, but can help you work through the problem quicker.
  • SUBMIT SOLUTION is used to submit your code against the final scoring tests.

    You will be notified once you have successfully passed the test cases for the challenge. Once you are comfortable with your solution, use the NEXT CHALLENGE or REVIEW ASSESSMENT button to move on.


Code Challenge Solver UI Layout
Code Challenge Solver UI Layout

The challenge solver is divided into 5 main areas, going counter-clockwise from the top:

  1. Commands
  2. Your Solution code editor
  3. Sample Tests code editor
  4. Results Pane. (If your screen isn't very tall, the results pane is moved to a tab in section 5)
  5. Help & Settings tabs

You can adjust the layout of the 4 main sections by dragging the bar between them.


Shortcut Key Commands

  • CTRL + Enter: Submit your solution against the final tests.
  • CTRL + ': Submit your solution against your own tests.
  • CTRL + U: Toggle focus between editors.


You can reset either your solution, the sample tests, or both.

Changing Languages

Some challenges are available in multiple languages. You may change the language using the dropdown located within the top action bar.

Submit Solution

Submit Solution Button
Submit Solution Button

Submitting your solution will cause it to be validated against the challenge's own test cases. You can submit your solution as many times as needed, however the only test cases available for you to see are those that may have been provided to you by default.

Next Challenge / Review Assessment

Once you complete a challenge, you can use this button to continue to the next challenge or review the assessment for submission.

Run Tests

(Within the Sample Tests Editor)

Running tests will cause your solution to be validated against the test cases that you provide. Sometimes challenges will provide some starter test cases to help demonstrate the requirements for the challenge. These test cases may not be the same as those used for validating the challenge.

Code Editors

Our code editor is based on CodeMirror. It provides many of the features you may expect from a normal IDE, though it is much simpler.

You can use many of the keyboard commands you may expect from a normal editor, including highlighting a block of code and using Tab to indent and Shift + Tab to unindent. For some languages, we have also implemented a simplified code completion.

Testing Framework

You can edit the sample tests, which are run against a framework selected by the company when setting up your challenges. You can see which framework is being used in the upper-right of the Sample Test Fixtures section. Clicking on the title will also open and load the reference docs file for that framework.

Full Screen

You can expand either code editor to completely fill the browser window using the full-screen arrows () located above the line numbers.


Execution Results Pane
Execution Results Pane

The results panel will give you details information about the tests that were run. If you have any tests that fail, you'll see a red bar and one or more red exclamation marks next to the failed tests.


On smaller screens, the results will appear as a tab alongside these instructions, rather than below.


Most compilation & runtime errors should show up automatically in the results pane.

For further debugging, you can write messages out to the console or system output. These messages will show up in the results pane.


Due to the solution code being executed in a short-lived container, Qualified does not currently support interactive debugging.

Help & Settings


Carefully read and follow the instructions in this panel for information on how to solve the assessment.

Your Notes

As you work on your solution, feel free to add detailed notes about how it works, reasoning behind your choices, documentation, etc.

This section is full-markdown enabled, so you can include lists, tables, code sections, etc.


You can browse help articles in the help pane like a mini web browser. The home button () will take you back to general help for the challenge solver.

If you need to see a help file large, click the new window icon ().

IDE Settings

The IDE settings tab lets you customize how the editor looks and works.

  • Theme: Light or Dark, depending on your mood.
  • Editor Mode: This allows you to enable Vim- or Emacs-like keyboard controls.
  • Tab Mode: We won't complain, choose the indentation style you prefer.
  • Line Wrapping: You can disable soft wraps, if you like to scroll horizontally.
  • Line Numbers: You can guess this one.
  • Auto Close Brackets: Typing certain brackets will cause the matching bracket to be added automatically.
  • Smart Indent: Enables IDE-like automatic indenting based on what characters you type.

    • Re-Indent When Typing Special Characters: Automatically adjusts indentation on certain characters.