Module 5: Creating Dynamic Web Pages with Scripting

Which of the following best describes client-side scripting?

• Runs on the web server

• Requires server requests for execution

• Executes in the user's browser

• Does not interact with HTML

Answer explanation

Client-side scripting refers to code that executes in the user's browser, allowing for dynamic interactions without needing to communicate with the server. This distinguishes it from server-side scripting, which runs on the web server.

What is the primary benefit of server-side scripting over client-side scripting?

• Faster execution

• Less processing load on the server

• Security of sensitive data

• Immediate response without server interaction

Answer explanation

The primary benefit of server-side scripting is the security of sensitive data, as it processes information on the server, reducing exposure to client-side vulnerabilities.

Which JavaScript data type is used to store multiple values in a single variable?

• Object

• Array

• String

• Number

Answer explanation

In JavaScript, an Array is a data type specifically designed to store multiple values in a single variable. Unlike Strings or Numbers, which hold single values, Arrays can hold lists of items, making them ideal for this purpose.

What is the correct syntax to display an alert box in JavaScript?

• alert("Hello World!");

• msg("Hello World!");

• display("Hello World!");

• show("Hello World!");

Answer explanation

The correct syntax to display an alert box in JavaScript is 'alert("Hello World!");'. The other options, msg, display, and show, are not valid JavaScript functions for this purpose.

Which of the following scenarios would use alert() effectively?

• Displaying a welcome message on page load

• Debugging JavaScript code

• Hiding and showing page content

• Building an interactive clock

Answer explanation

Using alert() to display a welcome message on page load is effective as it immediately captures the user's attention. The other options are better suited for different methods of interaction or debugging.

What error message does JavaScript return for syntax errors?

• ReferenceError

• SyntaxError

• TypeError

• RangeError

Answer explanation

In JavaScript, a SyntaxError is thrown when there is a syntax error in the code, indicating that the code cannot be parsed correctly. Therefore, the correct answer is SyntaxError.

What tool is most effective for debugging JavaScript errors in a browser?

• Notepad

• Browser Developer Tools

• FTP client

• Web server logs

Answer explanation

Browser Developer Tools are built into modern browsers and provide powerful features for debugging JavaScript errors, such as console logging, breakpoints, and inspecting elements, making them the most effective tool for this purpose.

Which JavaScript function retrieves the current time for a clock?

• getTime()

• new Date()

• setInterval()

• toLocaleTimeString()

Answer explanation

The correct choice is 'new Date()' as it creates a new Date object representing the current date and time. Other options do not directly retrieve the current time for a clock.

How would you dynamically update a clock every second using JavaScript?

• By calling setInterval()

• By using a for loop

• By reloading the page

• By writing a recursive function

Answer explanation

The correct choice is 'By calling setInterval()' because it allows you to execute a function at specified intervals, making it ideal for updating a clock every second. Other options do not provide a dynamic update mechanism.

Evaluate the following code: Does it correctly display the current time in an alert box?

let now = new Date();

alert(now.toTimeString());

• Yes, it displays the current time.

• No, it only displays the date.

• No, toTimeString() is incorrect.

• No, alert() cannot display time.

Answer explanation

The code correctly creates a Date object and uses toTimeString() to get the current time as a string. The alert function then displays this string, confirming that it indeed shows the current time.