Console.WriteLine("Maya Okonkwo");
Console.Write("Maya Okonkwo");
Console.WriteLine(" is on the roster.");

string playerName = "Maya Okonkwo";

Console.WriteLine(playerName);
Console.Write(playerName);
Console.WriteLine(" is on the roster.");

int screenWidth = 800;

int jerseyNumber = 24;

int jerseyNumber = "24";

1-5-card.cs(1,20): error CS0029: Cannot implicitly convert type 'string' to 'int'
The build failed. Fix the build errors and run again.

int gamesPlayed = 18.4;

1-5-card.cs(1,19): error CS0266: Cannot implicitly convert type 'double' to 'int'. An explicit conversion exists (are you missing a cast?)
The build failed. Fix the build errors and run again.

int jerseyNumber;
Console.WriteLine(jerseyNumber);

1-5-card.cs(2,19): error CS0165: Use of unassigned local variable 'jerseyNumber'
The build failed. Fix the build errors and run again.

double pointsPerGame = 24;
bool isCaptain = true;

Console.WriteLine(pointsPerGame);
Console.WriteLine(isCaptain);

24
True

'F' → Fullscreen

Build

Create a new C# program named 1-5-card, starting empty.

You are building a profile card — an athlete, a game character, a club officer, a driver, anyone with facts attached to them. Pick your own, and use real facts or invented ones.

Task 1: Stored Once, Used Twice

• Declare a string variable holding your subject's name.
• Print the name on its own line.
• Print a sentence that uses the name again, on one line of output.
• Run it.

The quotes appear exactly once in your program. Everywhere else you write the variable's name.

1
string playerName = "Maya Okonkwo";
2

3
Console.WriteLine(playerName);
4
Console.Write(playerName);
5
Console.WriteLine(" is on the roster.");

Maya Okonkwo
Maya Okonkwo is on the roster.

Task 2: Four Types, One Card

• Add an int, a double, and a bool, each holding a real fact about your subject.
• Give every variable a name that says what it holds.
• Build a card: a border, the name, a blank line, then one labeled line per fact.
• Keep the labels aligned. Use spaces inside the label strings.
• Finish with the sentence from Task 1.

Each label needs a Console.Write and each value a Console.WriteLine. That is the pattern from Activity 1.4, and it is how a label and a stored value share one line.

1
// Who this card is for
2
string playerName = "Maya Okonkwo";
3
int jerseyNumber = 24;
4
double pointsPerGame = 18.4;
5
bool isCaptain = true;
6

7
// Header
8
Console.WriteLine("=============================");
9
Console.Write("  ");
10
Console.WriteLine(playerName);
11
Console.WriteLine("=============================");
12
Console.WriteLine();
13

14
// Stat lines
15
Console.Write("Number:          ");
16
Console.WriteLine(jerseyNumber);
17
Console.Write("Points per game: ");
18
Console.WriteLine(pointsPerGame);
19
Console.Write("Team captain:    ");
20
Console.WriteLine(isCaptain);
21
Console.WriteLine();
22

23
// Sign-off, reusing the name
24
Console.Write(playerName);
25
Console.WriteLine(" is on the roster.");

=============================
  Maya Okonkwo
=============================

Number:          24
Points per game: 18.4
Team captain:    True

Maya Okonkwo is on the roster.

Task 3: One Edit, Every Line

• Count how many lines of your output contain the name. Write the number down.
• Change the name in the declaration — one line, one edit.
• Run it. Check that every one of those output lines changed.
• Do the same with the number: change the declaration only, and confirm the card follows.

You did not touch a single output statement. If you had typed the name into each line instead, you would have made that many edits and risked missing one.

Task 4: What the Types Refuse

• Put quotation marks around your int's value. Run it. Copy the error exactly.
• Fix it, then give your int a value with a decimal point. Run it. Copy that error exactly too.
• Fix it. Now delete the = value from one declaration, leaving only the type and name. Run it. Copy the third error.
• Fix it. Then set your double to a whole number and run it. Write down exactly what prints.
• Print your bool and write down exactly what prints, capital letters included.

Three of these are refused and two are allowed. The two that are allowed print something slightly different from what you might expect, and neither is a mistake.

The second error offers you a cast. Ignore it. We do not have casts until session 10, and reaching for one now means guessing at something that has a session of its own.

Task 5: Choose the Type

• For each fact below, decide which of the four types fits it. Write your answers down before you write any code.
• Then add two of them to your card, with labeled output lines.

One of these is a trap. A jersey number is written with digits, but nothing about it is ever counted or measured. Decide what you would do, and be ready to defend it either way.

1
// Who this card is for
2
string playerName = "Maya Okonkwo";
3
int jerseyNumber = 24;
4
double pointsPerGame = 18.4;
5
bool isCaptain = true;
6

7
// Two more facts, each stored as the type that fits it
8
string teamName = "Ridge Valley";
9
int gamesPlayed = 12;
10

11
// Header
12
Console.WriteLine("=============================");
13
Console.Write("  ");
14
Console.WriteLine(playerName);
15
Console.Write("  ");
16
Console.WriteLine(teamName);
17
Console.WriteLine("=============================");
18
Console.WriteLine();
19

20
// Stat lines
21
Console.Write("Number:          ");
22
Console.WriteLine(jerseyNumber);
23
Console.Write("Games played:    ");
24
Console.WriteLine(gamesPlayed);
25
Console.Write("Points per game: ");
26
Console.WriteLine(pointsPerGame);
27
Console.Write("Team captain:    ");
28
Console.WriteLine(isCaptain);
29
Console.WriteLine();
30

31
// Sign-off, reusing the name
32
Console.Write(playerName);
33
Console.WriteLine(" is on the roster.");

=============================
  Maya Okonkwo
  Ridge Valley
=============================

Number:          24
Games played:    12
Points per game: 18.4
Team captain:    True

Maya Okonkwo is on the roster.

Challenge (Optional)

• Add a second card for a different subject, reusing none of the first card's variables.
• Find out what happens if two variables are given the same name. Copy the error.
• Find out whether a variable name can start with a digit, or contain a space. Copy what you get.
• Store a value in a double with more decimal places than you expect it to keep, and see what prints.

Checkpoint

Before you submit, check all six:

• Your card declares at least one string, one int, one double, and one bool.
• Every variable name says what it holds.
• One value is used in at least two places, and its quotes or digits appear only once.
• Changing one declaration changed every output line that used it.
• Two facts from Task 5 are on the card, stored as the types you chose.
• All five Task 4 results are written down — three errors and two printed values.

The last one cannot be reconstructed by reading your program. Three of those results are compiler messages and two are output that differs from what the code looks like it should produce.

Reflection

Answer the following questions before submitting your work.

1. Putting quotation marks around a number made your program refuse to run. What does the type tell C# that lets it refuse before running anything at all?
2. Deleting = value from a declaration is an error, but the declaration still named a type and a name. In your own words, what is the difference between declaring a variable and initializing it?
3. How many output lines changed when you edited one declaration in Task 3? Why is that better than typing the value into each line?

Submit

Submit four things to the dropbox:

1. Your 1-5-card program file.
2. A copy of your card's output.
3. Your five Task 4 results, and your type choices from Task 5.
4. Your three reflection answers.

Activity Complete