Practice: Internal vs. External Scripts

Which tag and attribute combination correctly loads an external JavaScript file?

Answer explanation

External scripts use the script tag with the src attribute. The href attribute belongs to anchor and link tags, not script tags.

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Blooms Level: Remember

A team needs the same validation logic on five pages. Which approach reduces duplicate code?

• Write inline handlers on each input field

• Paste the function into each page's body

• Link one external .js file from each page

• Copy the script block into each page's head

Answer explanation

One external file linked by all pages keeps logic in a single location, so updates apply everywhere at once.

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Blooms Level: Apply

What benefit does an external script offer over an internal script for a large site?

• Bypasses the DOM tree entirely

• Can be cached by the browser

• Runs before the HTML parses

• Avoids the need for a script tag

Answer explanation

Browsers cache external .js files, so repeat visits load faster. Internal scripts re-download with every HTML request.

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Blooms Level: Understand

A script in the head queries an element that appears later in the body. What is the likely result?

• The query returns the body tag

• The element is created automatically

• The query returns null

• The query pauses until the element loads

Answer explanation

Head scripts run before body elements are parsed, so DOM lookups return null. Move the script to the bottom or use a load event to fix this.

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Blooms Level: Apply

Which TWO statements about external JavaScript files are correct?

• They cannot be used with HTML forms

• They are saved with a .js extension

• They must include their own script tags inside the file

• They run only after the user clicks a button

• They are linked using the src attribute

Answer explanation

External JS files use the .js extension and are referenced via src. Script tags belong in the HTML, not inside the .js file.

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Blooms Level: Understand

Where should a script tag be placed so it runs after all HTML elements are available?

• Inside the title element

• Inside the head element

• At the top of the document

• Just before the closing body tag

Answer explanation

Placing scripts before the closing body tag ensures the DOM is fully parsed first, so element lookups succeed without extra event listeners.

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Blooms Level: Remember

A developer has a few lines of test code used only on the homepage. Which choice fits best?

• A new external file linked to every page

• An internal script on that page only

• A separate external file linked in the head

• A minified library hosted on a CDN

Answer explanation

Page-specific, throwaway code belongs inline on that page. Creating an external file for one page adds an unneeded network request.

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Blooms Level: Apply

Why might a developer move a script from the head to just before the closing body tag?

• To allow the script to use the src attribute

• To make the script load faster from cache

• To let the HTML render before scripts run

• To prevent the script from being cached

Answer explanation

Scripts at the bottom let visible HTML appear first and ensure DOM elements exist before code touches them.

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Blooms Level: Understand

Which TWO situations favor using an internal script over an external file?

• Quick prototyping or a single demo page

• The script must be cached across the site

• The same code runs on twenty pages

• The script is shared by multiple developers

• Code is only a few lines and used once

Answer explanation

Internal scripts work well for tiny, single-page, or prototype code. Reuse, caching, and team sharing all favor external files.

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Blooms Level: Apply

How does the browser locate the file in ?

• Checks the operating system PATH variable

• Reads content inside the script tag body

• Resolves the path relative to the HTML page

• Searches the user's local downloads folder

Answer explanation

Relative src paths are resolved against the HTML document's URL, the same way image and stylesheet paths are located.

Tags

Blooms Level: Understand