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Difficulty - Medium

Total Plays - 50

Allowed Time - 10 sec

Best time - 1.638

Which data location is read-only by default?

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Explanation:
Calldata is immutable and cannot be modified by the callee. This makes it gas-efficient and safe for external function inputs

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Difficulty - Medium

Total Plays - 22

Allowed Time - 10 sec

Best time - 1.548 sec

What happens to storage slots after contract self-destruct?

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Explanation:
Storage is not automatically wiped when a contract self-destructs. The data remains on-chain and can be accessed again if a contract is redeployed at the same address.

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Difficulty - Medium

Total Plays - 25

Allowed Time - 10 sec

Best time - 1.455

Why is bytes32 cheaper than string in storage?

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Explanation:
bytes32 has a fixed 32-byte size and fits into a single storage slot. string is dynamically sized and requires additional storage pointers and length metadata.

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Difficulty - Medium

Total Plays - 25

Allowed Time - 10 sec

Best time - 3.228

Which operation resets a dynamic array length to zero?

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Explanation:
Using delete on a dynamic array sets its length to zero. Storage slots may remain allocated but become inaccessible through the array.

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Difficulty - Medium

Total Plays - 21

Allowed Time - 10 sec

Best time - 3.454

What does delete do to a mapping entry?

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Explanation:
Deleting a mapping key resets its value to the default type value. The key itself still exists conceptually since mappings do not track keys.

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Difficulty - Medium

Total Plays - 19

Allowed Time - 10 sec

Best time - 1.444

Which data location persists across transactions?

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Explanation:
Storage persists on-chain across transactions and blocks. Memory and calldata are temporary and cleared after execution completes.

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Vijay B
@xDhgFi3 • Dec 31, 2025

Dec 31, 2025
376

How would you approach breaking into protocol development as a final-year Solidity dev?

Hi everyone, I’m a final-year student and have been involved in Web3 since 2021. I spent close to two years interning with startups and am comfortable with Solidity (writing, debugging,...

Like 2 Replies 4
Sayali Bhandari
@SayaliB • Dec 30, 2025

Dec 30, 2025
2.2K

Stuck Between AI and Blockchain — Feels Like I Might Choose Wrong

I’m at a confusing point in my career and could use honest input from people who’ve been in the space longer. I’ve spent time learning blockchain basics and building small...

Like 5 Replies 4
Aditi Rao
@aditi-rao • Dec 28, 2025

Dec 28, 2025
514

Clean code, but still rejected — what do juniors miss in take-home assignments?

I’m a junior developer and I keep running into the same problem. My take-home assignments usually work, the code is clean, but I still get rejected — often without any...

Like 3 Replies 4
Difficulty - Medium

Total Plays - 20

Allowed Time - 10 sec

Best time - 4.491

What happens if a public variable name conflicts with a function name?

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Explanation:
Public variables automatically generate getter functions. If a function shares the same name, the compiler prioritizes the variable-generated getter, shadowing the function definition.

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Difficulty - Medium

Total Plays - 20

Allowed Time - 10 sec

Best time - 3.013 sec

Which keyword prevents further inheritance of a contract?

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Explanation:
Solidity does not support a final or sealed keyword for contracts. Any contract can be inherited unless architectural constraints are enforced manually.

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Difficulty - Medium

Total Plays - 17

Allowed Time - 10 sec

Best time - 3.845

Which function type cannot access msg.sender?

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Explanation:
pure functions cannot read blockchain context such as msg.sender or block.timestamp. They are restricted to computation based solely on input parameters and local variables

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Difficulty - Medium

Total Plays - 12

Allowed Time - 10 sec

Best time - 1.012 sec

What breaks if virtual is omitted in multiple inheritance?

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Explanation:
Without the virtual keyword, a function cannot be overridden in derived contracts. This breaks the override chain and prevents proper polymorphic behavior in multiple inheritance scenarios.

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Difficulty - Medium

Total Plays - 8

Allowed Time - 10 sec

Best time - 10

Which Solidity construct enforces compile-time immutability?

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Explanation:
constant variables are evaluated at compile time and embedded directly into contract bytecode. This guarantees immutability and avoids any runtime storage access or gas cost.

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Sayali Bhandari
@SayaliB • Dec 26, 2025

Dec 26, 2025
1.3K

When preparing for smart contract interviews, how much does gas optimization really matter?

I’m preparing for smart contract interviews and keep running into the same advice everywhere: learn gas optimization really well. I understand the basics — storage vs memory, packing variables, avoiding...

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Difficulty - Medium

Total Plays - 7

Allowed Time - 10 sec

Best time - 10

What default value does an uninitialized storage pointer hold?

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Explanation:
An uninitialized storage pointer defaults to storage slot zero. This can overwrite critical state variables such as ownership or balances, making it a high-severity audit issue.

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Difficulty - Medium

Total Plays - 7

Allowed Time - 10 sec

Best time - 10

Which visibility allows internal calls but blocks inheritance override?

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Explanation:
private functions and variables are accessible only within the defining contract. They cannot be called or overridden by child contracts, which blocks inheritance-based modification entirely.

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Difficulty - Medium

Total Plays - 5

Allowed Time - 10 sec

Best time - 6.667 sec

What happens if a modifier reverts after _ execution?

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Explanation:
If a modifier reverts after the _ placeholder executes, the entire transaction is reverted. All state changes made inside the function and modifier are rolled back due to Ethereum’s atomic execution model.

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Difficulty - Medium

Total Plays - 7

Allowed Time - 10 sec

Best time - 3.892

Which Solidity keyword prevents state variable shadowing?

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Explanation:
The override keyword forces explicit acknowledgment when a derived contract replaces a parent variable or function. This prevents accidental state variable shadowing in inheritance hierarchies, which can otherwise lead to subtle storage corruption bugs.

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Shehnaz Hussain
@shehnaz • Dec 23, 2025

Dec 23, 2025
2.0K

How to switch to blockchain testing? Key skills, tools, and career scope?

I'm trying to move into blockchain QA but not sure where to begin. I’ve spent the last 5 years working in manual software testing, and recently, I’m planning to switch...

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