I have a function with 4 return values which are in different types. Within the same contract, I want another function get this return values. For example,
function myFunction1() returns (uint, string, address){ ...... } funtion myFunction2(){ String s = myFunction1(); } I want string s get the second value returned by myFunction1. How can I do that?
See the section on "destructuring assignments and returning multiple values" in the Solidity documentation.
As an example:
function f() returns (uint, bool, uint) { return (7, true, 2); } function g() { // Declares and assigns the variables. Specifying the type explicitly is not possible. var (x, b, y) = f(); } However, it should be noted that you can't return dynamically sized values, as per this previous answer.
Here is the official example from the latest version of Solidity:
pragma solidity >0.4.23 <0.5.0; contract C { uint[] data; function f() public pure returns (uint, bool, uint) { return (7, true, 2); } function g() public { // Variables declared with type and assigned from the returned tuple. (uint x, bool b, uint y) = f(); // Common trick to swap values -- does not work for non-value storage types. (x, y) = (y, x); // Components can be left out (also for variable declarations). (data.length,,) = f(); // Sets the length to 7 } } Note that you can now use dynamically sized values.
Furthermore, the var keyword has been deprecated.
