Short-circuiting in conditions in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the balance is positive before sending funds.

Blockchain / Solidity

if (balance [1] 0) {
    sendFunds();
}

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

A<

B!=

C>

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using equality operator instead of greater than

Checking if balance is less than zero

The condition should check if balance is greater than zero to proceed with sending funds.

2fill in blank

medium

Complete the code to short-circuit and avoid division by zero.

Blockchain / Solidity

if (denominator != 0 && numerator [1] denominator) {
    processResult();
}

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

A==

B>

C<

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using greater than or less than instead of equality

Not checking denominator first

The code checks if numerator equals denominator only if denominator is not zero, avoiding division by zero errors.

3fill in blank

hard

Fix the error in the condition to short-circuit correctly when checking user authorization.

Blockchain / Solidity

if (isAdmin() [1] isOwner()) {
    grantAccess();
}

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

A&

B||

C&&

D|

Attempts:

3 left

💡 Hint

Common Mistakes

Using logical AND instead of OR

Using bitwise operators

The logical OR operator || short-circuits and grants access if either isAdmin() or isOwner() returns true.

4fill in blank

hard

Fill both blanks to create a short-circuit condition that checks if the contract is active and the caller is authorized.

Blockchain / Solidity

if (contract[1]active && caller[2]authorized) {
    executeTransaction();
}

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

A.

B==

C!=

D&&

Attempts:

3 left

💡 Hint

Common Mistakes

Using comparison operators instead of dot

Using logical operators inside property access

Accessing properties uses the dot operator .. Both contract.active and caller.authorized check the status.

5fill in blank

hard

Fill all three blanks to create a short-circuit condition that checks if the user is verified, has enough tokens, and the transaction amount is positive.

Blockchain / Solidity

if (user[1]verified && tokens [2] amount && amount [3] 0) {
    processPayment();
}

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

A.

B>=

C>

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using equality instead of comparison

Using dot operator incorrectly

The dot operator . accesses user.verified. The tokens must be greater or equal to the amount, and the amount must be greater than zero.