Debugging an application during development

In this section, you will learn how to debug problems at development time.

Creating an application with a deliberate bug

Add a new console application project named Debugging.

Modify the template code to look like this:

using static System.Console; 
 
namespace Debugging 
{ 
   class Program 
   { 
      static double Add(double a, double b) 
      { 
         return a * b; // deliberate bug! 
      } 
 
      static void Main(string[] args) 
      { 
         double a = 4.5; // or use var 
         double b = 2.5; 
         double answer = Add(a, b); 
         WriteLine($"{a} + {b} = {answer}"); 
         ReadLine(); // wait for user to press ENTER 
      } 
   } 
} 

Run the console application and view the output:

4.5 + 2.5 = 11.25

There is a bug: 4.5 added to 2.5 should be 7 and not 11.25!

We will use the debugging tools in Visual Studio 2017 or Visual Studio Code to squash the bug.

Setting a breakpoint

Breakpoints allow us to mark a line of code that...