Solana basics - Test | RedDuck Academy

01.

In Anchor, what is the primary purpose of the IDL

It describes the program’s instructions, accounts, and types so clients and tests can call the program in a type-safe way

It replaces Rust source code during deployment so validators can execute the program without a .so file

It is a Solana runtime file that assigns compute unit budgets to each instruction automatically

It stores program metadate

02.

You write #[account(init, payer = user, space = 8 + MyAccount::INIT_SPACE)]. What does the 8 + part represent?

The size of a Solana account’s lamport balance field

Anchor’s account discriminator prefix

The bump seed stored on-chain for PDAs

The length prefix of a dynamic String field

The length prefix of init macro

03.

Why might a Solana program store each item in a list as its own account instead of growing one big account?

Solana accounts have a max size. Unbounded in-account arrays can hit that limit

Solana forbids dynamic arrays in accounts

Clients cannot read data from a single large account

Iteration of the unbounded arrays is really slow

04.

Two different developers derive an address for their programs using the same seed bytes [b"vault", user_pubkey]What happens?

They get the same address, because seeds are deterministic

They get different addresses. The program ID is part of the derivation

Derivation fails. Seeds should be unique

05.

A client builds a transaction where the fee payer is a PDA derived from your program. Will Solana accept it?

Yes, if the PDA holds enough SOL and the program approves the spend

Yes, but only when the PDA is marked isSigner: true in the transaction

No. The fee payer must be a normal keypair that can sign the transaction

Yes, only if caller is owner of the PDA

06.

You create an account at a PDA address derived from your program’s ID. Which statement is correct?

PDA owner is your program

PDA doesn't have an owner because it's not on curve

The System Program owns all PDAs

You own a PDA