Blockchain Developer Certification Practice

When calling a getter for a public array, what is required?

1. A string argument

2. No arguments are needed

3. Two arguments of types uint256 and string

4. One argument of type uint256

The correct answer is: One argument of type uint256

When calling a getter for a public array in Solidity (the primary language used for writing smart contracts on Ethereum), you only need to provide an index to access an element within the array. The index is specified as a single argument of type uint256, which indicates the position of the element you want to retrieve. Public arrays in Solidity automatically generate getter functions that allow external contracts and users to access the elements of the array individually. For example, if you have a public array of integers, calling the generated getter function with a uint256 argument (the index) provides you with the value stored at that position in the array. This design ensures type safety and proper access management, as arrays can have multiple elements, and each element can be retrieved using its respective index. Indicating the need for a uint256 argument aligns with how arrays are typically accessed in programming, providing a straightforward and efficient method for retrieving data from storage.