setState for local state in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to update the counter when the button is pressed.

Flutter

int _counter = 0;

void _incrementCounter() {
  setState(() {
    _counter [1] 1;
  });
}

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

A+=

B-=

C*=

D/=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-=' will decrease the counter instead of increasing it.

Forgetting to put the update inside setState so UI won't refresh.

We use += to add 1 to the counter inside setState so the UI updates.

2fill in blank

medium

Complete the code to call setState and update the message string.

Flutter

String _message = 'Hello';

void _changeMessage() {
  [1](() {
    _message = 'Hi there!';
  });
}

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

ArefreshUI

BchangeState

CsetState

DupdateState

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong method name like updateState or refreshUI.

Not calling setState at all, so UI won't update.

setState is the Flutter method to tell the framework to rebuild the widget with new data.

3fill in blank

hard

Fix the error in the code by completing the setState call correctly.

Flutter

int _count = 0;

void increment() {
  setState [1] {
    _count++;
  }
}

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

A[ ]

B< >

C{ }

D( )

Attempts:

3 left

💡 Hint

Common Mistakes

Using curly braces directly after setState without parentheses causes syntax error.

Using square brackets or angle brackets instead of parentheses.

setState requires parentheses around the function, like setState(() { ... }).

4fill in blank

hard

Fill both blanks to correctly update the boolean flag inside setState.

Flutter

bool _isOn = false;

void toggle() {
  setState([1] {
    _isOn [2] !_isOn;
  });
}

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

A()

B[]

C{}

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets or angle brackets instead of parentheses for setState.

Not using curly braces for the function body.

The setState method requires parentheses () around the function, and the function body uses curly braces {}.

5fill in blank

hard

Fill all three blanks to correctly update a list inside setState.

Flutter

List<String> _items = [];

void addItem(String item) {
  setState([1] {
    _items.[2](item);
  });
}

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

A()

Badd

CaddAll

D[]

Attempts:

3 left

💡 Hint

Common Mistakes

Using addAll instead of add adds multiple items, not one.

Forgetting parentheses for setState causes errors.

We call setState with parentheses (). To add one item to the list, use add.