Test your skills: variables

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这个能力测试用于评估你自己是否理解了 如何存储你需要的信息 — 变量 这篇文章.

Note: You can try out solutions in the interactive editors below, however it may be helpful to download the code and use an online tool such as CodePen, jsFiddle, or Glitch to work on the tasks.

如果你遇到问题需要我们帮助 — 请前往在这一页的底部的 Assessment or further help 部分.

Note: In the examples below, if there is an error in your code it will be outputted into the results panel on the page, to help you try to figure out the answer (or into the browser's JavaScript console, in the case of the downloadable version).

Variables 1

In this task we want you to:

  • Declare a variable called myName.
  • Initialize myName with a suitable value, on a separate line (you can use your actual name, or something else).
  • Declare a variable called myAge and initialize it with a value, on the same line.

Try updating the live code below to recreate the finished example:

Download the starting point for this task to work in your own editor or in an online editor.

Variables 2

In this task you need to add a new line to correct the value stored in the existing myName variable to your own name.

Try updating the live code below to recreate the finished example:

Download the starting point for this task to work in your own editor or in an online editor.

Variables 3

The final task for now — in this case you are provided with some existing code, which has two errors present in it. The results panel should be outputting the name Chris, and a statement about how old Chris will be in 20 years' time. How can you fix the problem and correct the output?

Try updating the live code below to recreate the finished example:

Download the starting point for this task to work in your own editor or in an online editor.

Assessment or further help

You can practice these examples in the Interactive Editors above.

If you would like your work assessed, or are stuck and want to ask for help:

  1. Put your work into an online shareable editor such as CodePen, jsFiddle, or Glitch. You can write the code yourself, or use the starting point files linked to in the above sections.
  2. Write a post asking for assessment and/or help at the MDN Discourse forum Learning category. Your post should include:
    • A descriptive title such as "Assessment wanted for Variables 1 skill test".
    • Details of what you have already tried, and what you would like us to do, e.g. if you are stuck and need help, or want an assessment.
    • A link to the example you want assessed or need help with, in an online shareable editor (as mentioned in step 1 above). This is a good practice to get into — it's very hard to help someone with a coding problem if you can't see their code.
    • A link to the actual task or assessment page, so we can find the question you want help with.