Chapter quiz · JS Basic

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8 questions on JS Basic. Pass 70% to clear the chapter.

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Quiz

JS Basic — Chapter Quiz

Eight questions covering everything in the JS Basic chapter.

0/ 9

Question 1
1
What is the main purpose of JavaScript?
ATo style web pagesBTo add interactivity and logic to web pagesCTo structure web contentDTo store data on a server
JavaScript adds behavior — interactivity, logic, dynamic updates. HTML structures content, CSS styles it.
Question 2
2
Which HTML element is used to embed JavaScript in a page?
A<javascript>B<js>C<script>D<code>
JavaScript code lives inside <script> tags — either inline or via <script src="…"> for an external file.
Question 3
3
What does this code log?
```
console.log("Hello, " + "world!");
```
AHello,world!BHello, world!C"Hello, world!"Dundefined
+ concatenates the two strings. The space lives inside the first string, so the output is Hello, world! with a space.
Question 4
4
JavaScript is case-sensitive — myVar and myvar are different names.
TTrueFFalse
JavaScript is case-sensitive everywhere — identifiers, keywords, property names. myVar ≠ myvar ≠ MYVAR.
Question 5
5
Which keyword declares a variable whose value cannot be reassigned?
AletBconstCvarDstatic
const declares a constant binding. Reassigning throws TypeError. let and var allow reassignment.
Question 6
6
A single-line comment in JavaScript starts with ___.
// starts a single-line comment. For multi-line use /* … */.
Question 7
7
Which of these are valid JavaScript variable names?
Select all that apply.
AfirstNameB_tempC2ndD$elEclass
Names must start with a letter, _, or $ — then letters, digits, _, or $. 2nd is invalid (starts with a digit). class is invalid (reserved keyword).
Question 8
8
Which is the best way to display data on the page while debugging?
Adocument.write()Balert()Cconsole.log()DA <script> tag
console.log() writes to the developer console without disturbing the user or modifying the page — the standard debugging tool. alert is intrusive; document.write after page load erases the document.