Rollups (Optimistic vs ZK) in Blockchain / Solidity - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a rollup type variable.

Blockchain / Solidity

let rollupType = '[1]';

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

AOptimistic

BZK

CSidechain

DSharding

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing Optimistic with ZK rollups.

Using unrelated terms like Sidechain or Sharding.

The variable rollupType should be set to Optimistic to represent an Optimistic Rollup.

2fill in blank

medium

Complete the code to check if a rollup uses zero-knowledge proofs.

Blockchain / Solidity

if (rollupType === '[1]') {
  console.log('This rollup uses zero-knowledge proofs.');
}

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

AZK

BOptimistic

CPlasma

DStateChannel

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for Optimistic instead of ZK.

Using unrelated rollup types.

The condition should check for ZK to identify zero-knowledge proof rollups.

3fill in blank

hard

Fix the error in the function that returns the rollup's verification method.

Blockchain / Solidity

function getVerificationMethod(type) {
  return type === '[1]' ? 'Fraud Proofs' : 'SNARKs';
}

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

ARollup

BOptimistic

CZK

DPlasma

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for ZK instead of Optimistic.

Using generic terms like Rollup.

The function should check if the type is Optimistic to return 'Fraud Proofs'.

4fill in blank

hard

Fill both blanks to create a dictionary mapping rollup types to their verification methods.

Blockchain / Solidity

const verificationMethods = {
  Optimistic: '[1]',
  ZK: '[2]'
};

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

AFraud Proofs

BSNARKs

CPlasma

DSidechain

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the verification methods.

Using unrelated terms like Plasma or Sidechain.

Optimistic rollups use Fraud Proofs, and ZK rollups use SNARKs for verification.

5fill in blank

hard

Fill all three blanks to filter rollups that use fraud proofs and map their names.

Blockchain / Solidity

const rollups = [
  { name: 'Optimism', type: '[1]' },
  { name: 'Arbitrum', type: 'Optimistic' },
  { name: 'zkSync', type: 'ZK' }
];

const fraudProofRollups = rollups
  .filter(r => r.type === '[2]')
  .map(r => r.[3]);

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

AOptimistic

Cname

Dtype

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'ZK' instead of 'Optimistic' for filtering.

Mapping the wrong property like 'type'.

Both blanks 1 and 2 should be Optimistic to filter fraud proof rollups, and name is used to map their names.