0.4 First Day Assignment

Overview

The purpose of this assignment is to introduce you to the concept of assigning values to fields
and debugging in Visual Studio.

Copy and rename First Day 0.3

In Programming Concepts we will be building off of the previous week's assignment so
we will be copying over assignments regularly. It will be very important to make sure
your previous assignment is correct or the mistakes will follow you to the next
assignment.
A. In your First Day folder, copy the 0.3 parent folder and paste it.
0.4 First Day 1 Snip CopyFolder.png
B. Rename the folder to 0.4
0.4 First Day 1 Snip RenameFolder.png
C. Inside the folder, rename the .sln file from 0.3 to 0.4
0.4 First Day 1 Snip RenameSln.png
D. Double click the .sln file to open it in Visual Studio. Go to top
Debug the Book object field values.
A. Run the application. B. Click 'New Student', 'Have Breakfast' and then 'Fill Backpack'. Note that we have a bunch
of labels but no information.

No Field Values
C. Set a breakpoint on line 94, the closing curly brace of the FillBackpackButton event
handler. You can set a breakpoint by clicking in the space to the left of the line number.
Resource
- 0.4.1 How to Debug Using Breakpoints
Breakpoints stop the application at a specific point in time. This allows us to see
specific values while the application is running.

Set Breakpoint
D. Run the application. Click 'New Student', 'Have Breakfast' and then 'Fill Backpack'. The
debugger stops at the breakpoint.

Debugger
E. In the Autos window, expand the this.Student.Backpack.Book object.
Resource
- 0.4.2 How to Debug Using Autos
If you do not see the Autos Window, go to Debug | Windows | Autos.

Autos Window

The Autos Window shows the "best guess" of what the debugger thinks you want to
see. It shows you the Name of the object/field, the Value of the object/field and it's
Type. In this case, we have an object of 'this.Student.Backpack.Book' with the Value
of {FrstDayScenario.Book} (which signifies it's an object), and a Type of Book. The
Book object also has a number of Fields such as AuthorName, Cost, etc. In this case,
all the Values shown are default values because we have not assigned anything to
them.
F. Stop the application. Go to top
Assign a value to a field.
Resource
- 0.4.3 How to Assign a Value to a Field
A. Below, the line that has the new Book(); in it, paste the code below.
```
this.Student.Backpack.Book.AuthorName = "Andrew Stellman";
```
Assign AuthorName

In English this would read, "The Student's Backpack's Book's AuthorName is the
value 'Andrew Stellman'."
B. Run the application. Click the 'New Student', 'Have Breakfast' and 'Fill Backpack' buttons. C. Expand the Book object in the Autos Window. Now the AuthorName field has a Value of
"Andrew Stellman".

AuthorName Value
D. Since the application is stopped we need to make it start again manually. Click this
Continue button (F5) on the top menu.

Continue Button
E. The Author label now has the Value we gave AuthorName.

Author Value
Go to top
Use Intellisense to assign a value.

Visual Studio has a built in "hint giver" called Intellisense that shows us what we can
use/do. It can make life a lot easier, but can also lead you down the wrong path.
A. Under the lines of code that assigns the AuthorName value, type this.
Resource
- 0.4.4 How to Use Intellisense and the 'dot' Operator
Resource
- 0.4.5 How to Use the "this" Keyword
Type this.

Intellisense will bring up a list of things that are in the current instance of the current
class. Since Student is a field in the MainWindow class and we just assigned a
Student field on the line before, Intellisense "guesses" that that is what we want to
use.
B. Select Student from the list by either clicking it or pressing enter. It will automatically write
it for you. C. Type . after Student to bring up all this things available to the Student field/object. These
are sometimes referred to the members of an object/class.

Student Fields

Note that Intellisense shows the fields for the Student class.

Student Class
D. Select Backpack from the list. E. Type . after Backpack to bring up the list of things that Backpack has and select the Book. F. Type . after Book and select Cost.. G. We've reached the field we want to assign a value to so add a space and type an = sign.
In C# the = sign DOES NOT mean "equals" it means "assign to".

Cost Field
H. After the = sign type 38.32m;
Resource
- 0.4.6 How to Assign Primitive Values
The "m" after a number indicates that the value is a decimal type.

Cost Value
I. Run the application. Click the 'New Student', 'Have Breakfast' and 'Fill Backpack' buttons. J. In the Autos Window, check that the Cost Value is 38.32.

Cost Value
K. Press F5 to force the application to Continue. Now the Cost label has a value. L. Stop the application. Remove the breakpoint by clicking it. Go to top
Use debugging tools to check values.
A. Below the lines of code that we've added, copy and paste the code below.
```
this.Student.Backpack.Book.CourseTitle = "Programming Concepts";
this.Student.Backpack.Book.NumberOfPages = 784;
this.Student.Backpack.Book.Title = "Head First C#";
this.Student.Backpack.Book.Weight = 3.2;
```
Remaining Book Values
B. Set a breakpoint on the lines that assigns the AuthorName (87).

Set Breakpoint
C. Run the application. Click the 'New Student', 'Have Breakfast' and 'Fill Backpack' buttons. D. Expand the Book object in the Autos Window.

Autos Window - Book

Even though we have code that assigns values to the Book's Fields, since the
debugger has stopped on line 87 none of those lines of code have executed. Even the
AuthorName hasn't been assigned a value even though the debugger is on that line.
The line will only execute after the debugger moves off that line.
E. Execute lines of code while debugging. 1. While in debug mode, click the Step Over button on the top menu.
Resource
- 0.4.6 - How to Debug Using Step Over (F10)
Step Over

This executes the lines of code and moves the debugger down but does not
change the breakpoint.
2. Note that in the Autos Window, the AuthorName Value changes from null to what
we've assigned it to and is red to indicate that it has just changed.
Resource
- 0.4.8 How to Work With Default Values
AuthorName Value Changed
3. Press F10. This is the same as clicking the Step Over button. You will most likely need
to use the 'fn' key for this.

Cost Value Change (F10)
4. Continue to press F10 to see the values change or stop the application. Go to top
Submit to the Feedback System.
A. Close out of Visual Studio. B. Zip up the folder containing the .sln and project files.
0.4 First Day 6 Snip ZipFolder.png
C. Open the Feedback System Website. D. Navigate to the assignment and upload the zip file. E. Ensure you get a Success message. F. Copy and paste the URL to Canvas. Go to top