Intro to JavaScript

Podcast

Play an AI-generated podcast conversation about this lesson

Download our mobile app to listen on the go

Get App

Questions and Answers

What primary function does JavaScript serve in web development?

Defining the structure and content of web pages.
Managing server-side operations and database interactions.
Programming the behavior and interactions of web pages. (correct)
Specifying the visual layout and style of web pages.

With which technologies does JavaScript directly interact to enhance web pages?

Both HTML and CSS (correct)
Only HTML
Neither HTML nor CSS
Only CSS

What is the primary role of HTML in the context of web development?

To manage server-side operations.
To define the content and structure of web pages. (correct)
To control the interactivity of web elements.
To specify the layout and styling of web pages.

What is the correct way to embed JavaScript code directly within an HTML document?

<p>Using the <code><script></code> tags. (D)</p> Signup and view all the answers

What is the purpose of a JavaScript function?

<p>To execute a block of JavaScript code when 'called'. (D)</p> Signup and view all the answers

In HTML, where can you include the `<script>` tag to embed JavaScript?

<p>Either in the <code><head></code> or <code><body></code> section. (A)</p> Signup and view all the answers

In the following HTML snippet, what will be the result of clicking the button?

<p id="demo">A Paragraph</p>
<button type="button" onclick="myFunction()">Try it</button>

<p>The text 'A Paragraph' will change to 'Paragraph changed.' (C)</p> Signup and view all the answers

Consider the following code:

<!DOCTYPE html>
<html>
<head>
<script>
function myFunction() {
  document.getElementById("demo").innerHTML = "Paragraph changed.";
}
</script>
</head>
<body>

<h2>Demo JavaScript in Head</h2>
<p id="demo">A Paragraph</p>
<button type="button" onclick="myFunction()">Try it</button>

</body>
</html>

What happens when the 'Try it' button is clicked?

<p>The text 'A Paragraph' will change to 'Paragraph changed.'. (C)</p> Signup and view all the answers

What is a key advantage of using external JavaScript files?

<p>They allow for better separation of HTML and code. (D)</p> Signup and view all the answers

What file extension is typically used for external JavaScript files?

<p>.js (D)</p> Signup and view all the answers

How do you link an external JavaScript file to an HTML document?

<p>Using the <code><script></code> tag with the <code>src</code> attribute. (D)</p> Signup and view all the answers

What is a primary benefit of using cached JavaScript files?

<p>Faster page load times. (A)</p> Signup and view all the answers

Which of the following is NOT an advantage of using external JavaScript files?

<p>It automatically executes before HTML, ensuring faster initial rendering. (C)</p> Signup and view all the answers

In the context of JavaScript and HTML, what does the term 'event' refer to?

<p>An action or occurrence that happens in the system you are programming., (A)</p> Signup and view all the answers

If a JavaScript function is placed in the `<head>` section of an HTML document, how is it typically executed?

<p>It must be called explicitly, often in response to an event. (B)</p> Signup and view all the answers

Assume the following javascript code exists in an external file called `myscript.js`: `document.getElementById("myH").innerHTML = "paragraph changed";` Which of the following HTML code snippets would correctly import and execute this code?

<p><code><script src="myscript.js"></script></code> (B)</p> Signup and view all the answers

What is the correct term for incorporating Javascript code directly between the `<script>` tags within an HTML file?

<p>Internal Scripting (A)</p> Signup and view all the answers

Which of the following is the role of CSS in web development, alongside HTML and JavaScript?

<p>To specify the layout and styling of the web page. (D)</p> Signup and view all the answers

Which statement is true regarding the placement of external script references?

<p>They can be placed in either the <code><head></code> or the <code><body></code>. (A)</p> Signup and view all the answers

Given an HTML document with a button, what attribute is typically used to specify a JavaScript function that should run when the button is clicked?

<p>onclick (A)</p> Signup and view all the answers

Why is JavaScript considered an essential language for web developers?

<p>It is one of the core languages needed to program the behavior of web pages. (B)</p> Signup and view all the answers

Which of the following can JavaScript be used for?

<p>Calculating, manipulating, and validating data on websites. (D)</p> Signup and view all the answers

What does the `document.getElementById()` method do in JavaScript?

<p>It retrieves an HTML element based on its ID. (B)</p> Signup and view all the answers

What should a developer consider when deciding whether to place a `<script>` tag in the `<head>` or `<body>`?

<p>The timing and need for the script; scripts in <code><head></code> load before content and must be event-triggered, whereas those in <code><body></code> load with the content. (A)</p> Signup and view all the answers

What is a benefit of linking the same `.js` file to multiple HTML pages?

<p>Improves code separation and reusability. (D)</p> Signup and view all the answers

Flashcards

What is JavaScript?

JavaScript is the programming language of the web.

JavaScript's role in web development

HTML defines the content, CSS specifies the layout, and JavaScript programs the behavior of web pages.