C# 7 and .NET Core Cookbook

How to do it...

1. The following code example will illustrate how we used to have to use TryParse to check if a string value is a valid integer. You will notice that we had to declare the integer variable intVal, which was used as the out variable. The intVal variable would just sort of hang there in mid air, usually not initialized and waiting to be used in  TryParse.

        string sValue = "500";        int intVal;        if (int.TryParse(sValue, out intVal))        {          WriteLine($"{intVal} is a valid integer");          // Do something with intVal        }

2. In C# 7.0 this has been simplified, as can be seen in the following code example. We can now declare the out variable at the point where it is passed as an out parameter, like so:

        if (int.TryParse(sValue, out int intVal)) { ...