Solidity Programming Resources Quiz

1. Which programming language is primarily used for writing smart contracts on Ethereum?

• Solidity
• JavaScript
• Ruby
• Python

2. What is the standard file extension for Solidity programming files?

• .sl
• .solidity
• .slt
• .sol

3. Can multiple smart contracts be defined within a single Solidity file?

• Only one
• No
• Depends on size
• Yes

4. What are the main components that make up a Solidity smart contract`s layout?

• The structure consists of only state variables and modifiers.
• It includes only events and fallback functions.
• The typical layout includes a pragma statement, contract declaration, state variables, and functions.
• The layout comprises only address and mapping declarations.

5. What distinguishes state variables from local variables in Solidity?

• Local variables are stored permanently.
• State variables exist only during function execution.
• Local variables are accessible globally.
• State variables are stored on the blockchain.

6. What are the visibility levels for functions in Solidity from most restrictive to least?

• Internal, public, private, external
• Private, internal, external, public
• Public, external, internal, private
• External, private, public, internal

7. How can you throw an error with a message in Solidity?

• Use the throw keyword.
• Use the error string.
• Use the assert function.
• Use the require statement.

8. What two main artifacts does the Solidity compiler output after compiling a contract?

• The source code and the context
• The user guide and the binary
• The ABI and the bytecode
• The interface and the algorithm

9. How does one manage dates within a Solidity contract?

• Use address data types.
• Use uint variables.
• Use string variables.
• Use array data types.

10. Which keyword is used to get the current timestamp in seconds in Solidity?

• now
• timestamp
• time
• current

11. How can a timestamp for one day in the future be calculated in Solidity?

• now + 84600
• now + 8640s
• now + 86400
• now + 8640

12. Name the two methods to define custom data types in Solidity.

• Map and Set
• Class and Object
• List and Tuple
• Struct and Enum

13. What format do hexadecimal literals take in Solidity?

• hex:1a
• hex(1a)
• hex`1A`
• hex`1a`

14. Can you list the different units of Ether available in Solidity?

• Wei, kwei, gwei, mwei, microether, milliether, ether
• Ether, milliunit, terawatt, gigadime
• Kiloether, tinke, decimether, centigwei
• Microether, centiether, millidime, gimine

15. What time measurement units can be utilized in Solidity programming?

• Year, month, fortnight, moment
• Millisecond, decade, century, age
• Second, minute, hour, day, week
• Quarter, millenia, tick, span

16. How are storage variables characterized in Solidity?

• Storage variables are temporary and not saved permanently.
• Storage variables exist only during function execution.
• Storage variables are stored on the blockchain and are permanent.
• Storage variables are stored in the user`s local environment.

17. Differentiate between uint8 and uint16 in terms of value range in Solidity.

• uint8 stores a number up to 2^6-1, while uint16 stores a number up to 2^10-1.
• uint8 stores a number up to 2^7-1, while uint16 stores a number up to 2^15-1.
• uint8 stores a number up to 2^8+1, while uint16 stores a number up to 2^14+1.
• uint8 stores a number up to 2^8-1, while uint16 stores a number up to 2^16-1.

18. What is the distinction between private and public variables in Solidity?

• Both private and public variables can be accessed by any external entity.
• Private variables are visible to all contracts, while public variables are hidden.
• Public variables can only be accessed within the contract, while private variables are global.
• Private variables can be accessed only within the contract, while public variables are accessible externally.

19. How do view functions differ from pure functions in Solidity?

• View functions read state variables, while pure functions do not.
• View functions modify state variables, while pure functions do not read them.
• View functions return external data, while pure functions only return local data.
• View functions are always public, while pure functions are always private.

20. What are the definitions of structs and arrays in Solidity?

• A struct is a type of function, while an array is a variable type.
• A struct is a collection of heterogeneous data, while an array is a collection of homogeneous data.
• A struct is used for fixed sizes, while an array is for dynamic sizes.
• A struct is a simple data type, while an array is a complex type.

21. How much Ether is represented by 1 gwei in Solidity?

• 0.00000001 ETH
• 0.0001 ETH
• 0.01 ETH
• 0.000000001 ETH

22. What is the value of 1 wei of Ether in Solidity?

• 1 wei is equal to 1 ETH.
• 1 wei is equivalent to 10^-18 ETH.
• 1 wei equals 0.000001 ETH.
• 1 wei equals 0.1 ETH.

23. How is 1 kwei of Ether expressed in Solidity?

• 1 kwei is equal to 0.0001 ETH.
• 1 kwei is equal to 0.00000001 ETH.
• 1 kwei is equal to 0.01 ETH.
• 1 kwei is equal to 0.000001 ETH.

24. What is the definition of implicit conversion in the context of Solidity?

• Implicit conversion creates a new instance of the variable type.
• Implicit conversion is forced and may lose information.
• Implicit conversion involves explicit casting by the developer.
• Implicit conversion takes place if it makes sense semantically and no information is lost.

25. What does explicit conversion entail in Solidity?

• Explicit conversion is the process of simplifying a complex data structure.
• Implicit conversion occurs automatically when types are compatible.
• Explicit conversion can be done using casting or constructor-like syntax when the compiler is not allowing implicit conversion.
• Explicit conversion happens only during runtime checks.

26. Describe how error handling functions typically operate within Solidity.

• Solidity only checks for syntax errors during the execution of the smart contract, with no state reverting.
• Solidity provides various functions for error handling, where syntax errors are checked at compile time, and runtime errors are difficult to catch and occur while executing the smart contract. When an error occurs, the state is reverted back to its original state.
• Solidity handles errors by ignoring them and allowing the execution to continue irrespective of error occurrence.
• Errors in Solidity are always fatal, requiring manual intervention to fix them, without automatic state recovery.

27. What actions do revert() and revert(string reason) perform in Solidity?

• Both functions abort the contract execution and revert state changes, with one providing a reason.
• Both functions log the error but do not revert state changes.
• Only revert() does nothing and keeps state changes.
• Only revert(string reason) allows for state changes to remain.

28. Summarize the key differences between view and pure functions in Solidity.

• Pure functions can modify state, while view cannot.
• View and pure functions are identical in functionality.
• View functions can read state, while pure cannot.
• View functions can write state, while pure cannot.

29. Compare the value capabilities of uint8 with uint16 in Solidity.

• uint8 stores a number up to 2^8-1, while uint16 stores a number up to 2^16-1.
• uint16 is used for strings only.
• uint8 and uint16 hold the same value range.
• uint8 can store larger numbers than uint16.

30. How do private variables differ from public variables in Solidity?

• Public variables can only be accessed by the contract that declares them.
• Private variables can be accessed by any contract or external entity.
• Public variables can be modified and accessed only within the contract that declares them.
• Private variables can only be accessed within the contract that declares them.