Modifying Data Elements

You can change the values of data items using the Data, Smart Data, Inspector, or Watches windows during the course of your debugging sessions. You can modify program data values during a debugging session as a way to test hypothetical bug fixes during a program run. If you find that a modification fixes a program error, you can exit the debugging session, fix your program code accordingly, and recompile the program to make the fix permanent.

When you modify the value of a variable, the modification is effective for that specific program run only; the changes you make through the Data or Watches windows do not affect your program source code or the compiled program. To make your change permanent, you must modify your program source code in the Source Editor, then recompile your program.

The new value needs to be type-compatible with the variable you want to assign it to. A good rule of thumb is that if the assignment would cause a compile-time or run-time error, it is not a legal modification value.

To modify the value of a variable in the Data window:

Open the Data window while the debugger is stopped at a breakpoint.
Right-click an item in the Data window and choose Modify Value from the context menu.
The Modify Value dialog appears with the selected item's name and its current value.
Enter a new value for the item.
- If you are modifying a primitive value, you can enter a new value.
- If you are modifying a reference pointer (other than a string), you can enter the memory address of an existing object or array.
- If you are modifying a string, you can enter either a new string value or the memory address of an existing string.
Click Help for more information.
Click OK to change the value for the item and to close the dialog.
The new value appears in the Data, Smart Data, Inspector, or Watches windows.