ID attribute in HTML - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add an ID attribute to the <div> element.

HTML

<div [1]="header">Welcome!</div>

Drag options to blanks, or click blank then click option'

Aid

Bclass

Cstyle

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using class instead of id

Forgetting the attribute name

Using style or name attributes incorrectly

The ID attribute is added using id="value" inside the tag.

2fill in blank

medium

Complete the code to link a label to an input using the ID attribute.

HTML

<label for="[1]">Name:</label>
<input type="text" id="nameInput">

Drag options to blanks, or click blank then click option'

AuserName

BinputName

CnameInput

DtextInput

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching the for and id values

Using class instead of id

Leaving the for attribute empty

The label's for attribute must match the input's id exactly.

3fill in blank

hard

Fix the error in the code by completing the ID attribute correctly.

HTML

<section [1]="main-section">Content here</section>

Drag options to blanks, or click blank then click option'

Aname

Bclass

Cstyle

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the attribute value

Using class instead of id

Missing the attribute name

The id attribute value must be in quotes: id="main-section".

4fill in blank

hard

Fill both blanks to create a button with an ID and a label linked to it.

HTML

<label for="[1]">Click me</label>
<button [2]="btn1">Press</button>

Drag options to blanks, or click blank then click option'

Abtn1

Bbutton

Cid

Dclass

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching for and id values

Using class instead of id

Leaving one attribute missing

The label's for attribute and button's id attribute must match.

5fill in blank

hard

Fill all three blanks to create a section with an ID, a heading with the same ID, and a paragraph.

HTML

<section [1]="intro">
  <h2 [2]="intro">Welcome</h2>
  <p>[3]</p>
</section>

Drag options to blanks, or click blank then click option'

Aid

CThis is the introduction paragraph.

Dclass

Attempts:

3 left

💡 Hint

Common Mistakes

Using class instead of id

Not matching the id values

Leaving paragraph empty

Both section and h2 use id="intro"; paragraph has text content.

Practice

1. What is the main purpose of the id attribute in HTML?

easy

A. To uniquely identify one element on the page

B. To add a class to multiple elements

C. To create a hyperlink to another page

D. To add inline styles to an element

Solution

1. Step 1: Understand the role of the id attribute

   The id attribute is used to give a unique name to one element on the page.

2. Step 2: Compare with other attributes

   Unlike classes, which can be shared by many elements, id must be unique and identifies only one element.

3. Final Answer:

   To uniquely identify one element on the page -> Option A

4. Quick Check:

   ID attribute = unique element identifier [OK]

Hint: ID is for one unique element only [OK]

Common Mistakes:

• Thinking ID can be used on multiple elements
• Confusing ID with class attribute
• Using ID to add styles to many elements

2. Which of the following is the correct way to add an ID to a div element?

easy

A.

B.

C.

D.

Solution

1. Step 1: Check correct syntax for ID attribute

   The ID attribute must be written as id='value' with quotes around the value.

2. Step 2: Identify the correct option

   <div id='header'></div> uses correct syntax with quotes and equals sign. <div id header></div> misses equals sign, and D uses wrong colon syntax.

3. Final Answer:

   <div id='header'></div> -> Option D

4. Quick Check:

   ID attribute syntax = id='value' [OK]

Hint: ID attribute needs quotes and equals sign [OK]

Common Mistakes:

• Omitting quotes around ID value
• Using colon instead of equals sign
• Confusing class and ID syntax

3. What will be the visible result in the browser for this HTML snippet?

<style>#title { color: red; }</style>
<h1 id='title'>Welcome</h1>
<h1 id='title'>Hello</h1>

medium

A. Only the second heading appears in red

B. Neither heading appears in red

C. Both headings appear in red

D. Only the first heading appears in red

Solution

1. Step 1: Understand ID uniqueness and CSS application

   The CSS targets the element with id='title'. IDs should be unique, but here two elements share the same ID.

2. Step 2: Browser behavior with duplicate IDs

   Browsers apply styles to all elements matching the selector, even if IDs are duplicated, so both headings get red color.

3. Final Answer:

   Both headings appear in red -> Option C

4. Quick Check:

   CSS applies styles to all matching elements regardless of ID uniqueness [OK]

Hint: Duplicate IDs style all matching elements in CSS [OK]

Common Mistakes:

• Assuming all elements with same ID get styled differently
• Thinking IDs prevent CSS styling on duplicates
• Ignoring browser behavior on duplicates

4. Identify the error in this HTML snippet:

<div id='main'>Content</div>
<div id='main'>More Content</div>

medium

A. Missing closing tags

B. Using the same ID on multiple elements

C. Incorrect attribute name

D. ID value should be a number

Solution

1. Step 1: Check for ID uniqueness

   The snippet uses id='main' on two different div elements, which breaks the rule that IDs must be unique.

2. Step 2: Verify other syntax

   Tags are properly closed, attribute names are correct, and ID values can be any string, so no other errors apply.

3. Final Answer:

   Using the same ID on multiple elements -> Option B

4. Quick Check:

   ID must be unique per element [OK]

Hint: Each ID must be unique on the page [OK]

Common Mistakes:

• Reusing same ID on multiple elements
• Confusing ID with class for multiple elements
• Thinking ID values must be numeric

5. You want to create a navigation menu where each link scrolls to a different section on the same page. Which is the correct way to use the id attribute to achieve this?

hard

A. Assign unique IDs to each section and use <a href='#id'> to link

B. Use the same ID on all sections and link with <a href='#id'>

C. Use classes on sections and link with <a href='.class'>

D. Use inline styles to scroll to sections

Solution

1. Step 1: Understand linking with IDs

   To link to a part of the page, each target section must have a unique id attribute.

2. Step 2: Use anchor links with href='#id'

   The links use href='#id' to jump to the section with that ID. Using unique IDs ensures correct navigation.

3. Final Answer:

   Assign unique IDs to each section and use <a href='#id'> to link -> Option A

4. Quick Check:

   Unique IDs + href='#id' = page section links [OK]

Hint: Unique IDs + href='#id' create page anchors [OK]

Common Mistakes:

• Using same ID on multiple sections
• Trying to link with classes in href
• Using styles instead of IDs for navigation