TypeError：返回参数类型元组（int_const 23，bool，uint8 [3]内存）不可转换为预期类型元组（uint256，bool，uint256 [3]内存）

Question

//When I compile and deploy below code. It gives me no error

// SPDX-License-Identifier: MIT 
pragma solidity ^0.8.0; 
contract MultipleValues{
function returnValues() public pure returns (uint, bool, uint8[3] memory) {
    return (23, true, [1,2,3]);
}
}

//But when I change value from uint8[3] to uint[3] then it throws error

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
contract MultipleValues{function returnValues() public pure returns (uint, bool, uint[3] memory) {
return (23, true, [1,2,3]);
}
}

//how to resolve this issue?
//Unexpected behaviour of array in solidity when returning a fixed size array

Answer 1

this should work:

contract MultipleValues{
    function returnValues() public pure returns (uint, bool, uint[3] memory) {
        uint[3] memory memoryArray;
        memoryArray[0]=1;
        memoryArray[1]=2;
        memoryArray[2]=3;
        return (23, true, memoryArray);
}

uint types in solidity are uint8,uint16,uint24,.....,uint256 . The smallest one is uint8 and when the compiler sees "[1,2,3]" it infers the smallest uint type which is uint8 . Actually "[1,2,3]" can be any of uint8,uint16,uint24,.....,uint256

What I did was, explicitly told the compiler that I am creating "uint[3]" and returning it.