Solidity Interview Questions for Freshers

Explore the list of interview questions with answers for Solidity. Here you will find all the beginner-level questions that you will face during the interview.

1. What is Solidity?

Solidity is an object-oriented programming language developed by Christian Reitwiessner, Alex Beregszaszi, and several former Ethereum core contributors for implementing smart contracts on various blockchain platforms like Ethereum. It is used to implement smart contracts that implement business logic and generates a chain of transaction records in the blockchain system. 

2. What are the important features of Solidity?

• Solidity is a statically-typed object-oriented language.
• It is highly influenced by Python, C++, and JavaScript which runs on EVM.
• It is designed for implementing smart contracts.
• It can be used for implementing contracts for functionalities like Voting, Crowdfunding, Multi-signature wallets, etc.
• Solidity is a primary language for blockchain platforms.

3. What extension does the source file have in Solidity?

The Solidity contract file/ library file has an extension .sol. For example, w3wiki.sol. The SOL script is a file that is programmed in Solidity programming language in the same way files are created in C++ or any other programming language. The SOL file contains the solidity source code and is used to create smart contracts for the transactions on the blockchain.

4. What type of language is Solidity?

Solidity is a statically-typed high-0level object-oriented programming language designed for developing smart contracts that run on Ethereum Virtual Machine (EVM). 

5. Why is Solidity used in Blockchain?

Solidity is designed to develop smart contracts for transactions on the Blockchain. 

• It is used to create smart contracts that implement business logic.
• Smart contracts can be used for various purposes like multi-signature wallets, Voting, Bind auctions, Crowdfunding, etc.
• Smart contracts can be used to automate transactions on the blockchain.

6. What is a smart contract?

Smart contracts are computer programs stored on the blockchain that are executed when the predetermined conditions are met. 

• These are used to automate the execution so that all the participants can be immediately certain of the outcome.
• Smart contracts can automatically trigger the next action when the conditions are met.
• They remove the need for intermediaries to handle the transactions.
• Smart contracts don’t require any paperwork to process as they are digital and automated.  

7. What is a gas limit in Solidity?

A gas limit in Solidity refers to the maximum amount of gas a user is willing to spend on a transaction. When creating a transaction on the Ethereum Network user must specify the gas limit to ensure that they don’t spend more gas than they intend.

• If a transaction requires more gas than the specified gas limit, the transaction will be reverted, and the used gas will not be refunded.
• If a transaction requires less than the gas limit, the remaining gas will be returned to the user.

8. What is a variable in Solidity?

A variable in Solidity is a storage location that can contain values. These values can be changed during runtime. Variables are broadly classified as state variables and local variables.

• State variables are the variables that are declared outside any function in a contract and are permanently stored on the Ethereum blockchain.
• Local variables are the variables that are declared within the function and their scope is limited to that function.

9. What is an event in Solidity?

An event is an inheritable member of the contract, which stores the arguments passed in the transaction logs when emitted.

• Generally, events are used to inform the calling application about the current state of the contract, with the help of the logging facility of EVM.
• Events notify the applications about the change made to the contracts and applications which can be used to execute the dependent logic.

10. What is a library in Solidity?

Libraries in solidity are similar to contracts that contain reusable codes. A library has functions that can be called by other contracts.

• Deploying a common code by creating a library reduces the gas cost.
• Functions of the library can be called directly when they do not modify the state variables i.e. only pure and view functions can be called from outside of the library.
• The library does not have state variables, it cannot inherit any element and cannot be inherited.

Solidity is an object-oriented programming language used to implement smart contracts on blockchain platforms like Ethereum, which generates transaction records in the system. To excel in your journey toward top companies as a Solidity developer, you need to master some important Solidity Interview Questions to crack their Solidity Online Assessment Round and Solidity Interview Round. We have prepared a list of the Top 50 Solidity Interview Questions along with their answers to ace in interviews.

In this article, we have covered all the essential questions that are likely to be asked in interviews, whether you are a beginner embarking on your journey to become a Solidity Engineer/developer or a seasoned professional seeking a job change and aiming to refresh important concepts in line with current trends. Then this Interview guide is for you.

This Solidity Interview Questions article is designed for all skill levels, from beginners and intermediates to advanced candidates, encompassing a wide range of interview questions.