c# return both list of string and list of generic type-CodePudding

I need to return multiple items from a function. How can I do that?

public List<string> GetInfo()
{
    var result = new List<string>();

    return result;
}

How can I return something like this? Basically List of string and maybe also a list of generic type.

public List<string> GetInfo()
{
    var result = new List<string>();

    return result and someType;
}

public class someType
{
    public List<SomeOthertype> someOthertype { get; set; }
}

CodePudding user response：

If I understand you right, you can try using named tuples:

public (List<string> result, List<SomeOthertype> other) GetInfo()
{
    var result = new List<string>();

    someType instance = new someType();

    //TODO: put relevant code here

    // we return both result and someOthertype in one tuple 
    return (result, instance.someOthertype);
}

Usage:

var info = GetInfo();

var result = info.result;
var other = info.other;

CodePudding user response：

I would propose to use a generic method to be possible use different types:

public static (List<string>, List<U>) GetInfo<U>()
{
    var list = new List<string>();
    var another = new List<U>();
    //...
    return (list, another);
}

CodePudding user response：

From c# 7 onward there are tuple value types that are the cleanest way to return multiple values from the function.

Pre c# 7 you can use out parameters