Define variable in try block C#-CodePudding

I don't want to have ultra-deep nested blocks, so in cases that variable initialisation could error I would prefer to do it like this:

try
{
    var foo = JsonConvert.DeserializeObject<...>(...);
}
catch (JsonReaderException)
{
   Console.Write(...);
   throw;
}
var bar = GetBar(foo);

Of course it doesn't compile, I'm not allowed to use foo outside of the try-block that initialises it.

Putting a full type specification right above the block also sucks imo:

List<Dictionary<string, List<(Dictionary<int, int>, Dictionary<string, string>)>>> foo;
try
{
    foo = GetFoo();
}
catch (FooException)
{
   Console.Write(...);
   throw;
}
var bar = GetBar(foo);

Even in less extreme cases like just int foo = 0; already feels dirty, especially with that confusing unused initial value. The catch block exits the program anyway.

How can I try-initialise a variable and use it outside of that scope, with minimal repetition and minimal characters typed?

CodePudding user response：

One way to do this would be putting the initialization logic into another method and wrap it with try/catch there, so then you can have:

var foo = InitializeFoo();
var bar = GetBar(foo);

private Foo InitializeFoo() 
{
     try {
         // initalize and return foo
     }
     catch {
        throw;
     }
}

You can generalize this by passing a delegate to the Initialize method that specifies the initiaze logic and use it for anything else.

public T InitializeVariable<T>(Func<T> initializeAction)
{
     try {
         var x = initializeAction();
         return x;
     }
     catch {
        throw;
     }
}

CodePudding user response：

A quick and dirty solution is to use dynamic instead of full type specification like this:

dynamic foo;