Section headers and footers in iOS Swift - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

What is the output of this code for section header title?

Given this UITableViewDataSource method, what will be shown as the header title for section 0?

iOS Swift

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

A "Fruits" for section 0, "Vegetables" for section 1

B "Vegetables" for section 0, "Fruits" for section 1

C No header titles shown

D Runtime error due to missing return

💡 Hint

Check the condition for section number in the return statement.

The method returns "Fruits" when section is 0, otherwise "Vegetables". So section 0 header is "Fruits".

❓ ui_behavior

intermediate

What will be the footer text for section 1 with this code?

Consider this UITableViewDelegate method. What footer text will appear for section 1?

iOS Swift

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

A "End of Vegetables" for all sections

B "End of Vegetables" for section 1 footer

C No footer text for any section

D App crashes due to nil return

💡 Hint

Look at the condition checking section number.

The method returns footer text only for section 1, nil for others, so only section 1 has footer text.

❓ lifecycle

advanced

Which method is called to customize a section header view?

To provide a custom UIView as a section header in UITableView, which delegate method should you implement?

A tableView(_:titleForHeaderInSection:)

B tableView(_:heightForHeaderInSection:)

C tableView(_:viewForHeaderInSection:)

D tableView(_:willDisplayHeaderView:forSection:)

💡 Hint

Think about which method returns a UIView instead of a String.

The method tableView(_:viewForHeaderInSection:) returns a UIView to use as the header view.

❓ navigation

advanced

What happens if you return nil in viewForFooterInSection?

If you implement tableView(_:viewForFooterInSection:) and return nil for a section, what will the table show?

A Default footer title is shown if titleForFooterInSection is implemented

B No footer view is shown for that section

C App crashes with nil view error

D Footer view from previous section is reused

💡 Hint

Check interaction between viewForFooterInSection and titleForFooterInSection methods.

If viewForFooterInSection returns nil, the table uses titleForFooterInSection to show a default footer title if available.

📝 Syntax

expert

What error occurs with this incorrect header method signature?

Identify the error in this UITableViewDelegate method signature for section header view:

iOS Swift

func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView {
  return UIView()
}

A No error, code compiles and runs

B Method name is incorrect

C Return type UIView is invalid, should be String

D Missing optional return type causes compile error

💡 Hint

Check the return type expected by the delegate method.

The delegate method expects an optional UIView? return type, not a non-optional UIView.

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