if in switch

Question

Hello anybody,
Is it possible to use a if in a switch?

switch (eingabe)  
                    {  
                        //Path check/create  
                        if(!System.IO.Directory.Exists($@"{localappdata}\Liquid Aqua\API"))  
                        {  
                            System.IO.Directory.CreateDirectory($@"{localappdata}\Liquid Aqua\API");  
                        }  
break;  

  

Answer 1

Hi Robin,

Yes, but you would still need to have the "case" statement, because otherwise, there's no point in using the "switch". Something like this:

switch (eingabe)  
{  
    case "SomeValue of eingabe":  
         //Path check/create  
         if(!System.IO.Directory.Exists($@"{localappdata}\Liquid Aqua\API"))  
         {  
             System.IO.Directory.CreateDirectory($@"{localappdata}\Liquid Aqua\API");  
         }  
        break;  
    case "SomeOther Value if needed":  
        // do something  
        break;  
}  

Hope that helps.

Answer 2

Hello @RobinJ

If using C# 9 there is the switch expression, you can also use the following which you supply logic for each condition.

public static class Example  
{  
    public static bool Demo(int item, string folder) => item switch  
    {  
        1 => Operations.DoSomething1(folder),  
        2 => Operations.DoSomething2(folder),  
        _ => Operations.DefaultSwitch()  
    };  
}  
  
public class Operations  
{  
    public static bool DoSomething1(string folder)  
    {  
        if (Directory.Exists(folder))  
        {  
            return true;  
        }  
        else  
        {  
            Directory.CreateDirectory(folder);  
            return false;  
        }  
    }  
    public static bool DoSomething2(string folder) => /* do whatever*/ true;  
  
    public static bool DefaultSwitch() => false;  
}  

Here is a tad more robust example that shows returning a List with source in the following repository.

public static List<Employee> GetEmployeesWhereManagerHasYearsAsManager(this Person person) => person switch  
{  
    Manager { YearsAsManager: >=4 } manager => manager.Employees,  
    Manager { YearsAsManager: 3 } manager => manager.Employees,  
    _ => null  
};