Functions and arrow syntax in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a function that returns the sum of two numbers using arrow syntax.

Flutter

int add(int a, int b) => [1];

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

Aa - b

Breturn a + b

Ca + b

Dprint(a + b)

Attempts:

3 left

💡 Hint

Common Mistakes

Including the 'return' keyword after the arrow.

Using subtraction instead of addition.

Using print instead of returning a value.

The arrow syntax allows a concise function that returns the expression after the arrow. Here, a + b is returned.

2fill in blank

medium

Complete the code to define a function that returns true if a number is even using arrow syntax.

Flutter

bool isEven(int number) => number [1] 2 == 0;

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

A%

B+

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using division instead of modulo.

Using multiplication or addition which do not check evenness.

The modulo operator % returns the remainder. If number % 2 == 0, the number is even.

3fill in blank

hard

Fix the error in the arrow function that should return the length of a string.

Flutter

int getLength(String text) => [1];

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

Atext.length

Blength(text)

Ctext.length()

Dtext.size

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses like a method call.

Using non-existent properties like size.

Using a function call syntax.

In Dart, the length of a string is accessed as a property text.length, not as a method.

4fill in blank

hard

Fill the blank to define an arrow function that returns the square of a number.

Flutter

int square(int n) => n [1] n;

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

A/

B*

C-

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition or subtraction instead of multiplication.

Using division which does not square the number.

To square a number, multiply it by itself: n * n.

5fill in blank

hard

Fill all three blanks to create a function that returns a greeting message with a name.

Flutter

String greet(String name) => "Hello" [1] ", " [2] name [3] "!";

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

A+

B-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication operators for strings.

Forgetting to concatenate all parts.

String concatenation in Dart uses the + operator. The greeting combines "Hello, ", the name, and "!".