Section headers and footers in iOS Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of section headers in a UITableView?

Section headers help group related rows visually and provide a title or description for each group, making the list easier to understand.

intermediate

Which UITableViewDelegate method provides a view for a section header?

tableView(_:viewForHeaderInSection:) returns a UIView to display as the header for a given section.

intermediate

How do you set the height of a section footer in a UITableView?

Implement tableView(_:heightForFooterInSection:) in UITableViewDelegate and return the desired height in points.

beginner

True or False: Section footers can only display text, not custom views.

False. Section footers can display custom views by implementing tableView(_:viewForFooterInSection:).

intermediate

What happens if you return nil from tableView(_:viewForHeaderInSection:)?

The table view will display the default header, which can be a simple text label if you provide a title via tableView(_:titleForHeaderInSection:).

Which method sets the text title for a section header in UITableView?

A tableView(_:titleForHeaderInSection:)

B tableView(_:viewForHeaderInSection:)

C tableView(_:heightForHeaderInSection:)

D tableView(_:titleForFooterInSection:)

The method tableView(_:titleForHeaderInSection:) returns a simple text string to display as the section header title.

How can you provide a custom view for a section footer?

A Implement tableView(_:titleForFooterInSection:)

B Implement tableView(_:viewForFooterInSection:)

C Implement tableView(_:heightForHeaderInSection:)

D Implement tableView(_:cellForRowAt:)

To show a custom view for a footer, implement tableView(_:viewForFooterInSection:) and return your UIView.

What delegate method controls the height of a section header?

A tableView(_:titleForHeaderInSection:)

B tableView(_:heightForFooterInSection:)

C tableView(_:estimatedHeightForRowAt:)

D tableView(_:heightForHeaderInSection:)

tableView(_:heightForHeaderInSection:) lets you specify the height in points for the header of a section.

If you want no header for a section, what should you return from tableView(_:heightForHeaderInSection:)?

A 0

B CGFloat.leastNormalMagnitude

C UITableView.automaticDimension

D -1

Returning 0 from tableView(_:heightForHeaderInSection:) hides the header for that section.

Which of these is NOT a valid way to customize section headers?

A Providing a title string

B Returning a custom UIView

C Modifying the cellForRowAt method

D Changing the header height

cellForRowAt is for rows, not headers or footers.

Explain how to add a custom view as a section header in a UITableView.

Think about which delegate method returns a UIView for the header.

Describe the difference between providing a title and a custom view for section footers.

One is simple text, the other is a full view.

Practice

1. What is the main purpose of section headers and footers in a UITableView?

easy

A. To change the background color of the table view

B. To add animations between table cells

C. To handle user input events

D. To organize and label groups of rows for better readability

Solution

1. Step 1: Understand the role of section headers and footers

   Section headers and footers are used to separate and label groups of rows in a table view.

2. Step 2: Identify their effect on user experience

   They improve readability by clearly marking different sections, making the list easier to navigate.

3. Final Answer:

   To organize and label groups of rows for better readability -> Option D

4. Quick Check:

   Section headers and footers = organize groups [OK]

Hint: Headers and footers label groups in lists [OK]

Common Mistakes:

• Confusing headers with animations
• Thinking headers change colors only
• Assuming headers handle input

2. Which UITableViewDataSource method is used to provide a title for a section header?

easy

A. tableView(_:cellForRowAt:)

B. tableView(_:titleForHeaderInSection:)

C. tableView(_:heightForRowAt:)

D. tableView(_:didSelectRowAt:)

Solution

1. Step 1: Recall UITableViewDataSource methods for headers

   The method tableView(_:titleForHeaderInSection:) returns the text for the header of a section.

2. Step 2: Differentiate from other methods

   Other methods handle cells, row height, or selection, not headers.

3. Final Answer:

   tableView(_:titleForHeaderInSection:) -> Option B

4. Quick Check:

   Header title method = tableView(_:titleForHeaderInSection:) [OK]

Hint: Header titles use titleForHeaderInSection method [OK]

Common Mistakes:

• Choosing cellForRowAt for headers
• Confusing heightForRowAt with header titles
• Selecting didSelectRowAt which is for taps

3. Given this code snippet, what will be displayed as the footer text for section 1?

func tableView(_ tableView: UITableView, titleForFooterInSection section: Int) -> String? {
  if section == 0 {
    return "End of first section"
  } else if section == 1 {
    return "End of second section"
  }
  return nil
}

medium

A. "End of second section"

B. "End of first section"

C. nil (no footer text)

D. Runtime error

Solution

1. Step 1: Analyze the method for section 1

   The method checks if section == 1 and returns "End of second section" for that case.

2. Step 2: Confirm no errors or nil for section 1

   Since section 1 matches the else if condition, it returns the string, not nil or error.

3. Final Answer:

   "End of second section" -> Option A

4. Quick Check:

   Footer for section 1 = "End of second section" [OK]

Hint: Check section number in footer method [OK]

Common Mistakes:

• Confusing section 0 and 1
• Assuming nil means default text
• Expecting runtime error from this code

4. Identify the error in this code for adding a section header title:

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
  if section == 0 {
    return "First Section"
  }
}

medium

A. Using String instead of String?

B. Wrong method name for header title

C. Missing return statement for all code paths

D. Incorrect parameter types

Solution

1. Step 1: Check method return type and all paths

   The method returns String? but does not return anything if section != 0, causing a missing return error.

2. Step 2: Confirm method signature correctness

   The method name and parameters are correct; the issue is missing return for other sections.

3. Final Answer:

   Missing return statement for all code paths -> Option C

4. Quick Check:

   All paths must return a value [OK]

Hint: All function paths must return a value [OK]

Common Mistakes:

• Ignoring missing return for else cases
• Thinking method name is wrong
• Confusing return type with optional

5. You want to display a custom view as a section header instead of just text. Which UITableViewDelegate method should you implement?

hard

A. tableView(_:viewForHeaderInSection:)

B. tableView(_:titleForHeaderInSection:)

C. tableView(_:heightForRowAt:)

D. tableView(_:didSelectRowAt:)

Solution

1. Step 1: Identify method for custom header views

   The method tableView(_:viewForHeaderInSection:) allows returning a UIView to use as a header.

2. Step 2: Differentiate from text-only header method

   tableView(_:titleForHeaderInSection:) returns only a String, not a view.

3. Final Answer:

   tableView(_:viewForHeaderInSection:) -> Option A

4. Quick Check:

   Custom header view method = viewForHeaderInSection [OK]

Hint: Use viewForHeaderInSection for custom header views [OK]

Common Mistakes:

• Using titleForHeaderInSection for views
• Confusing row height with header view
• Thinking didSelectRowAt affects headers