函数返回多个值

// 函数可以返回多个值function multipleReturns() returns(uint a, uint b, uint c) {  return (1, 2, 3);}

同时接收所有返回值

function processMultipleReturns() {  uint a;  uint b;  uint c;  // 这样来做批量赋值:  (a, b, c) = multipleReturns();}

只接收部分返回值

// 或者如果我们只想返回其中一个变量:function getLastReturnValue() {  uint c;  // 可以对其他字段留空:  (,,c) = multipleReturns();}

项目中实际碰到问题

function multipleReturns() returns(string memory a, uint b, uint c) {      return ("1", 2, 3);    }        function processMultipleReturns() {      string memory a;      uint b;      uint c;      // 这样来做批量赋值:      (a, b, c) = multipleReturns();    }

mapping (uint256 => Tree) public dnaToTree;   //通过 Dna 获取加密资产详情     function getTreeByDna(uint256 _Dna) public constant returns(string memory treeByDna_user , uint256 treeByDna_dna,string memory treeByDna_treeName, uint64 treeByDna_birthTime, uint256 treeByDna_needFooder, bytes32  treeByDna_status, bool treeByDna_isAdult) {        return (dnaToTree[_Dna].user, dnaToTree[_Dna].dna, dnaToTree[_Dna].treeName, dnaToTree[_Dna].birthTime, dnaToTree[_Dna].needFooder ,dnaToTree[_Dna].status ,dnaToTree[_Dna].isAdult);    }        function getTreeByDna_d(uint256 _Dna) public constant {               string memory treeByDna_user;        uint256 treeByDna_dna;        string memory treeByDna_treeName;        uint64 treeByDna_birthTime;        uint256 treeByDna_needFooder;        bytes32 treeByDna_status;        bool treeByDna_isAdult;        (treeByDna_user, treeByDna_dna, treeByDna_treeName, treeByDna_birthTime, treeByDna_needFooder, treeByDna_status, treeByDna_isAdult) = getTreeByDna(_Dna);            }