Dimension bindings (clientWidth, clientHeight) in Svelte - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to bind the width of the div to the variable width.

Svelte

<script>
  let width = 0;
</script>

<div bind:[1]={width} style="background: lightblue; height: 100px;">
  Width: {width}px
</div>

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

AclientWidth

BclientHeight

CoffsetWidth

DscrollWidth

Attempts:

3 left

💡 Hint

Common Mistakes

Using bind:clientHeight instead of bind:clientWidth

Trying to bind to offsetWidth which is not supported by Svelte binding

Forgetting to use bind: prefix

In Svelte, bind:clientWidth binds the element's width to the variable.

2fill in blank

medium

Complete the code to bind the height of the section to the variable height.

Svelte

<script>
  let height = 0;
</script>

<section bind:[1]={height} style="background: lightgreen; width: 200px;">
  Height: {height}px
</section>

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

AclientHeight

BclientWidth

CoffsetHeight

DscrollHeight

Attempts:

3 left

💡 Hint

Common Mistakes

Using bind:clientWidth instead of bind:clientHeight

Trying to bind to offsetHeight which is not supported by Svelte binding

Not initializing the variable before binding

Binding clientHeight updates the variable with the element's height.

3fill in blank

hard

Fix the error in the code to correctly bind the width of the div to boxWidth.

Svelte

<script>
  let boxWidth = 0;
</script>

<div bind:[1]={boxWidth} style="background: coral; height: 150px;">
  Box width: {boxWidth}px
</div>

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

AclientHeight

BscrollWidth

CoffsetWidth

DclientWidth

Attempts:

3 left

💡 Hint

Common Mistakes

Using clientHeight instead of clientWidth

Using offsetWidth which is not supported for binding

Forgetting the bind: prefix

The correct binding for width is clientWidth. Using clientHeight or others will not bind width.

4fill in blank

hard

Fill both blanks to bind width and height of the article to width and height variables.

Svelte

<script>
  let width = 0;
  let height = 0;
</script>

<article bind:[1]={width} bind:[2]={height} style="background: lightyellow;">
  Size: {width}px wide and {height}px tall
</article>

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

AclientWidth

BclientHeight

CoffsetWidth

DoffsetHeight

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up width and height bindings

Using offsetWidth or offsetHeight which are not supported for binding

Forgetting to bind both properties

Use bind:clientWidth for width and bind:clientHeight for height bindings.

5fill in blank

hard

Fill all three blanks to create a reactive statement that updates area when width or height changes.

Svelte

<script>
  let width = 0;
  let height = 0;
  let area = 0;

  $: area = [1] * [2];
</script>

<div bind:clientWidth={width} bind:clientHeight={height} style="background: lavender;">
  Area: {area} px²
</div>

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

Awidth

Bheight

Carea

Dwidth + height

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition instead of multiplication

Using the variable area inside its own assignment

Mixing up width and height variables

The reactive statement multiplies width and height to update area.

Practice

1. What does the Svelte dimension binding bind:clientWidth do when used on an element?

easy

A. It disables resizing of the element.

B. It sets the element's width to a fixed pixel value.

C. It stores the current width of the element in a variable and updates it automatically when the element resizes.

D. It binds the element's width to the window's width.

Solution

1. Step 1: Understand what bind:clientWidth does

   This binding connects a variable to the element's width in pixels.

2. Step 2: Recognize automatic updates on resize

   The variable updates automatically when the element's size changes, reflecting the current width.

3. Final Answer:

   It stores the current width of the element in a variable and updates it automatically when the element resizes. -> Option C

4. Quick Check:

   Dimension binding tracks element size = D [OK]

Hint: Dimension bindings track element size automatically [OK]

Common Mistakes:

• Thinking it sets a fixed width
• Confusing element width with window width
• Assuming it disables resizing

2. Which of the following is the correct syntax to bind an element's height to a variable height in Svelte?

easy

A.

B.

C.

D.

Solution

1. Step 1: Recall Svelte binding syntax

   Bindings use bind:property={variable} to connect element property to variable.

2. Step 2: Identify correct syntax for clientHeight binding

   The correct form is bind:clientHeight={height} inside the element tag.

3. Final Answer:

   <div bind:clientHeight={height}></div> -> Option A

4. Quick Check:

   Binding syntax = bind:property={variable} [OK]

Hint: Use curly braces to bind variable: bind:clientHeight={var} [OK]

Common Mistakes:

• Omitting curly braces around variable
• Using attribute without binding syntax
• Writing bind:clientHeight without variable

3. Given this Svelte code snippet, what will be displayed when the <div> width is 300 pixels?

<script>
  let width = 0;
</script>

<div bind:clientWidth={width} style="width: 300px; height: 100px; background: lightblue;">Width: {width}px</div>

medium

A. Width: 0px

B. Width: 300px

C. Width: 100px

D. Width: undefined

Solution

1. Step 1: Understand binding effect on width variable

   The bind:clientWidth sets width to the element's actual width in pixels.

2. Step 2: Check element style width

   The div has inline style width of 300px, so width becomes 300.

3. Final Answer:

   Width: 300px -> Option B

4. Quick Check:

   bind:clientWidth updates width = 300px [OK]

Hint: bind:clientWidth reflects actual element width in pixels [OK]

Common Mistakes:

• Assuming initial variable value stays unchanged
• Confusing height with width
• Expecting undefined or zero without resize

4. Identify the error in this Svelte code that tries to bind the clientHeight to a variable height:

<script>
  let height;
</script>

<section bind:clientHeight>Height: {height}px</section>

medium

A. Missing curly braces to bind height variable to clientHeight.

B. Variable height should be initialized to 0.

C. The bind:clientHeight should be on a div, not section.

D. The variable height must be declared as const.

Solution

1. Step 1: Check binding syntax

   The binding must specify the variable with curly braces: bind:clientHeight={height}.

2. Step 2: Identify missing variable binding

   Here, bind:clientHeight is used without assigning it to height, so it won't update the variable.

3. Final Answer:

   Missing curly braces to bind height variable to clientHeight. -> Option A

4. Quick Check:

   Binding needs variable with curly braces = A [OK]

Hint: Always bind with variable: bind:clientHeight={height} [OK]

Common Mistakes:

• Omitting variable in binding
• Thinking variable must be initialized
• Assuming element type matters for binding

5. You want to create a responsive Svelte component that changes its background color based on its own width using bind:clientWidth. Which approach correctly implements this behavior?

hard

A. <script>
let width = 0;
</script>

<div bind:clientWidth={width} style="background: width > 200 ? 'lightgreen' : 'lightcoral'; width: 100%; height: 100px;">
Width: {width}px
</div>

B. <script>
let width = 0;
</script>

<div style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
Width: {width}px
</div>

C. <script>
let width = 0;
</script>

<div bind:clientWidth style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
Width: {width}px
</div>

D. <script>
let width = 0;
</script>

<div bind:clientWidth={width} style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
Width: {width}px
</div>

Solution

1. Step 1: Confirm correct binding syntax

   <script>
     let width = 0;
   </script>
   
   <div bind:clientWidth={width} style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
     Width: {width}px
   </div>

   uses bind:clientWidth={width}, correctly binding width variable.

2. Step 2: Check style expression syntax

   <script>
     let width = 0;
   </script>
   
   <div bind:clientWidth={width} style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
     Width: {width}px
   </div>

   uses a valid inline style with a ternary expression inside curly braces to change background color based on width.

3. Step 3: Identify errors in other options

   <script>
     let width = 0;
   </script>
   
   <div style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
     Width: {width}px
   </div>

   lacks binding, so width stays 0.

   <script>
     let width = 0;
   </script>
   
   <div bind:clientWidth style="background: {width > 200 ? 'lightgreen' : 'lightcoral'}; width: 100%; height: 100px;">
     Width: {width}px
   </div>

   misses variable in binding.

   <script>
     let width = 0;
   </script>
   
   <div bind:clientWidth={width} style="background: width > 200 ? 'lightgreen' : 'lightcoral'; width: 100%; height: 100px;">
     Width: {width}px
   </div>

   uses invalid style syntax without curly braces around expression.

4. Final Answer:

   Correctly binds width and uses proper style expression. -> Option D

5. Quick Check:

   Bind variable and use style expression correctly = A [OK]

Hint: Bind width variable and use curly braces for style expressions [OK]

Common Mistakes:

• Forgetting to bind variable
• Incorrect style expression syntax
• Using bind without variable assignment