In Solidity, delegatecall is a low-level function used to execute code from another contract while maintaining the context (i.e., storage, msg.sender, msg.value) of the calling contract.

delegatecall is a special type of message call used to execute functions of another contract, but it runs in the context of the calling contract. This means:

• The code of the target contract is executed.
• The target contract’s code is executed as though it’s part of the calling contract.
• The state (storage) and other context (like msg.sender and msg.value) are maintained from the calling contract.

Syntax of delegatecall

Here’s how delegatecall is typically used in Solidity:

(bool success, bytes memory returnData) = targetContract.delegatecall(data);

• targetContract: The address of the contract you want to delegate the call to.
• data: The ABI-encoded data (including function signature and parameters) that will be executed on the target contract.
• success: A boolean indicating whether the call was successful or not.
• returnData: The data returned by the function call (if any).

Usecase of delegateCall

1. Proxy contracts
2. Storing big contracts across multiple small contracts (because of the size limit of smart contracts)

Difference b/w CCIs and delegateCall