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blockchainethereumsoliditysmartcontracts

How to return mapping list in Solidity? (Ethereum contract)

I want to make a simple smart contract that has a list, can set item, and can get the list.

Code in solidity:

contract lister {
    mapping(int => string) list;
    int id = 0;
    
    function getList() returns ( /*HERE*/ ) {
        return list;
    }

    function setItemToList(string str) {
        list[id] = str;
        id++;
    }
}

I want to make getList() return the list, but the return type is not compatible. How can I do that?

Solution

  • Bulk access to lists/arrays/etc is painful in Solidity. You rarely see it in contracts. In your case, a possible solution is to provide a function to access one item, using its index, and to let the caller loop from 0 to id.