View and pure functions in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a view function that returns a stored number.

Blockchain / Solidity

function getNumber() public [1] returns (uint) {
    return storedNumber;
}

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

Aexternal

Bpure

Cpayable

Dview

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'pure' instead of 'view' when reading state variables.

Forgetting to specify 'view' or 'pure' for functions that don't modify state.

The view keyword indicates the function reads state but does not modify it.

2fill in blank

medium

Complete the code to declare a pure function that returns the sum of two numbers.

Blockchain / Solidity

function add(uint a, uint b) public [1] returns (uint) {
    return a + b;
}

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

Apayable

Bpure

Cview

Dexternal

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'view' instead of 'pure' when the function does not read state.

Omitting the keyword for functions that do not access state.

The pure keyword means the function neither reads nor modifies the blockchain state.

3fill in blank

hard

Fix the error in the function declaration to make it a view function.

Blockchain / Solidity

function getBalance() public [1] returns (uint) {
    return balance;
}

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

Aprivate

Bpayable

Cview

Dpure

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'pure' which disallows reading state variables.

Using 'payable' which is unrelated to reading state.

The function reads the state variable balance, so it must be marked as view.

4fill in blank

hard

Fill both blanks to create a pure function that returns the product of two numbers.

Blockchain / Solidity

function multiply(uint x, uint y) public [1] returns (uint) {
    return x [2] y;
}

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

Apure

Bview

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'view' instead of 'pure' for functions that do not access state.

Using '+' instead of '*' for multiplication.

The function does not read or modify state, so it is pure. The multiplication operator is *.

5fill in blank

hard

Fill all three blanks to create a view function that returns the length of a stored string.

Blockchain / Solidity

function getStringLength() public [1] returns (uint) {
    return [2].[3];
}

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

Aview

BstoredString

Clength

Dpure

Attempts:

3 left

💡 Hint

Common Mistakes

Marking the function as 'pure' when it reads state.

Using incorrect variable name or property for length.

The function reads the stored string variable storedString and returns its length. It must be marked view.