Call (Solidity Code Example)

call is a low level function to interact with other smart contracts.

This is the recommended method to use when you're just sending Ether via calling the fallback function.

However it is not the recommend way to call existing functions.

Few reasons why low-level call is not recommended

• Reverts are not bubbled up
• Type checks are bypassed
• Function existence checks are omitted

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.26;

contract Receiver {
    event Received(address caller, uint256 amount, string message);

    fallback() external payable {
        emit Received(msg.sender, msg.value, "Fallback was called");
    }

    function foo(string memory _message, uint256 _x)
        public
        payable
        returns (uint256)
    {
        emit Received(msg.sender, msg.value, _message);

        return _x + 1;
    }
}

contract Caller {
    event Response(bool success, bytes data);

    // Let's imagine that contract Caller does not have the source code for the
    // contract Receiver, but we do know the address of contract Receiver and the function to call.
    function testCallFoo(address payable _addr) public payable {
        // You can send ether and specify a custom gas amount
        (bool success, bytes memory data) = _addr.call{
            value: msg.value,
            gas: 5000
        }(abi.encodeWithSignature("foo(string,uint256)", "call foo", 123));

        emit Response(success, data);
    }

    // Calling a function that does not exist triggers the fallback function.
    function testCallDoesNotExist(address payable _addr) public payable {
        (bool success, bytes memory data) = _addr.call{value: msg.value}(
            abi.encodeWithSignature("doesNotExist()")
        );

        emit Response(success, data);
    }
}