Type Conversion

Conversion is possible both implicitly and explicitly in Solidity. If no data loss or contradiction in rules is anticipated, the Solidity compiler allows for implicit conversions. For example, uint8 can be implicitly converted to uint16 because both are unsigned integers, and the latter has a wider range. On the other hand, int8 can only be explicitly converted to uint256, even though int8 can hold negative values, which aren’t allowed in uint256. In such cases, explicit conversion is necessary to ensure that we’re aware of the data type changes in our code. This feature provides us with the flexibility to work seamlessly across different data types while maintaining the integrity of our smart contracts.

Why do we need type conversion?

We often need type conversion for the following reasons:

• Type safety: Solidity is a statically typed language, which means that the data type of a variable is established at compile-time. This ensures a level of safety in our code but also imposes restrictions on how we can manipulate different types of data. Conversions become necessary to make types compatible with each other.

• Resource optimization: In the blockchain world, storage and computational power come at a premium. Different types consume different amounts of storage. For example, uint8 uses less space than uint256. Being able to convert between types allows us to better optimize our resource usage.

• Interoperability: Our smart contracts might need to interact with other contracts or even different blockchains. These external entities might represent similar data using different types. In such cases, type conversion becomes essential for seamless interaction.

Using type conversion effectively, we can write more efficient and interoperable smart contracts.

Explicit type conversion

To explicitly change one data type to another in Solidity, we use constructors. For example: