Console.WriteLine and Write methods in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of mixed Write and WriteLine calls

What is the output of the following C# code?

C Sharp (C#)

Console.Write("Hello");
Console.WriteLine(" World");
Console.WriteLine("!");

A

!
dlroW olleH

B

Hello World!

C

Hello
 World
!

D

Hello World
!

💡 Hint

Remember that Write does not add a new line, but WriteLine does.

Console.Write writes text without moving to a new line. Console.WriteLine writes text and then moves to a new line. So the first Write prints "Hello" staying on the same line, then WriteLine prints " World" and moves to a new line, then the last WriteLine prints "!" and moves to a new line.

❓ Predict Output

intermediate

Output with multiple Write calls

What will be printed by this code snippet?

C Sharp (C#)

Console.Write("A");
Console.Write("B");
Console.WriteLine("C");
Console.WriteLine("D");

A

ABCD

B

ABC
D

C

A
B
C
D

D

AB
CD

💡 Hint

Write does not add a new line, WriteLine does.

The first two Write calls print 'A' and 'B' on the same line. Then WriteLine prints 'C' and moves to a new line. Finally, WriteLine prints 'D' and moves to a new line.

❓ Predict Output

advanced

Output of WriteLine with format string

What is the output of this code?

C Sharp (C#)

int x = 5;
int y = 10;
Console.WriteLine("Sum of {0} and {1} is {2}", x, y, x + y);

A

Sum of 5 and 10 is 15

B

Sum of {0} and {1} is {2}

C

Sum of 5 and 10 is {2}

D

Sum of x and y is 15

💡 Hint

Check how placeholders {0}, {1}, {2} are replaced by arguments.

The placeholders {0}, {1}, and {2} are replaced by the values of x, y, and x + y respectively. So the output is 'Sum of 5 and 10 is 15' followed by a new line.

❓ Predict Output

advanced

Effect of WriteLine with no arguments

What does this code print?

C Sharp (C#)

Console.Write("Line1");
Console.WriteLine();
Console.WriteLine("Line3");

A

Line1

Line3

B

Line1Line3

C

Line1
Line3

D

Line1
 Line3

💡 Hint

WriteLine with no arguments just moves to the next line.

Console.Write prints 'Line1' without a new line. Console.WriteLine() prints just a new line. Console.WriteLine("Line3") prints 'Line3' and moves to a new line. So the output has a blank line between Line1 and Line3.

❓ Predict Output

expert

Output of nested Write and WriteLine with escape sequences

What is the output of this code?

C Sharp (C#)

Console.Write("Start\n");
Console.WriteLine("Middle\tEnd");
Console.Write("Finish");

A

hsiniF
dnE	elddiM
tratS

B

Start

Middle	End
Finish

C

Start
Middle	End
Finish

D

hsiniF
dnE	elddiM

tratS

💡 Hint

Remember \n is newline and \t is tab. WriteLine adds a newline after printing.

Console.Write("Start\n") prints 'Start' and a newline but does not add an extra newline. Console.WriteLine("Middle\tEnd") prints 'Middle', a tab, 'End', then a newline. Console.Write("Finish") prints 'Finish' without newline. So the output lines are: Start Middle End Finish

Practice

1. What is the main difference between Console.WriteLine and Console.Write in C#?

easy

A. Console.WriteLine only prints numbers; Console.Write only prints strings.

B. Console.WriteLine prints text without a newline; Console.Write prints text and moves to a new line.

C. Console.WriteLine prints text and moves to a new line; Console.Write prints text but stays on the same line.

D. Console.WriteLine clears the console; Console.Write appends text.

Solution

1. Step 1: Understand Console.WriteLine behavior

   Console.WriteLine prints the given text and then moves the cursor to the next line.

2. Step 2: Understand Console.Write behavior

   Console.Write prints the given text but keeps the cursor on the same line, so the next output continues on that line.

3. Final Answer:

   Console.WriteLine prints text and moves to a new line; Console.Write prints text but stays on the same line. -> Option C

4. Quick Check:

   WriteLine adds newline, Write does not [OK]

Hint: WriteLine adds newline; Write stays on same line [OK]

Common Mistakes:

• Confusing which method adds a newline
• Thinking WriteLine does not move to next line
• Assuming Write clears the console

2. Which of the following is the correct syntax to print "Hello World" on the console and move to the next line?

easy

A. Console.Write("Hello World");

B. Console.WriteLine["Hello World"];

C. Console.WriteLine Hello World;

D. Console.WriteLine("Hello World");

Solution

1. Step 1: Check method usage with parentheses and quotes

   In C#, method calls require parentheses and string arguments must be in double quotes.

2. Step 2: Identify correct method for printing with newline

   Console.WriteLine("Hello World"); correctly prints the text and moves to the next line.

3. Final Answer:

   Console.WriteLine("Hello World"); -> Option D

4. Quick Check:

   Correct syntax uses parentheses and quotes [OK]

Hint: Use WriteLine with parentheses and quotes for new line [OK]

Common Mistakes:

• Missing parentheses after method name
• Using square brackets instead of parentheses
• Omitting quotes around string

3. What will be the output of the following C# code?

Console.Write("Hello ");
Console.WriteLine("World!");
Console.WriteLine("Goodbye!");

medium

A. Hello
World!
Goodbye!

B. Hello World!
Goodbye!

C. Hello World!Goodbye!

D. Hello
World!
Goodbye!

Solution

1. Step 1: Analyze first line with Console.Write

   Console.Write("Hello "); prints "Hello " and stays on the same line.

2. Step 2: Analyze second line with Console.WriteLine

   Console.WriteLine("World!"); prints "World!" on the same line and then moves to the next line.

3. Step 3: Analyze third line with Console.WriteLine

   Console.WriteLine("Goodbye!"); prints "Goodbye!" on a new line and moves to next line.

4. Final Answer:

   Hello World! Goodbye! -> Option B

5. Quick Check:

   Write stays, WriteLine adds newline [OK]

Hint: Write stays on line, WriteLine adds newline after output [OK]

Common Mistakes:

• Assuming WriteLine does not add newline
• Thinking Write moves to next line
• Confusing output line breaks

4. The following code is intended to print "12345" on the same line, but it prints each number on a new line instead. What is the error?

for (int i = 1; i <= 5; i++)
{
    Console.WriteLine(i);
}

medium

A. Use Console.Write instead of Console.WriteLine inside the loop.

B. Change the loop to start from 0 instead of 1.

C. Add a semicolon after the for loop declaration.

D. Use Console.ReadLine instead of Console.WriteLine.

Solution

1. Step 1: Understand the difference between Write and WriteLine in loop

   Console.WriteLine(i); prints the number and moves to a new line each time.

2. Step 2: Fix by using Console.Write to stay on the same line

   Replacing with Console.Write(i); prints numbers continuously on the same line.

3. Final Answer:

   Use Console.Write instead of Console.WriteLine inside the loop. -> Option A

4. Quick Check:

   Write stays on line, WriteLine adds newline [OK]

Hint: Use Write to print on same line inside loops [OK]

Common Mistakes:

• Using WriteLine when same line output is needed
• Adding unnecessary semicolons after for loop
• Confusing ReadLine with WriteLine

5. You want to print the numbers 1 to 3 on the same line separated by spaces, then print "Done" on the next line. Which code snippet achieves this correctly?

hard

A. for (int i = 1; i <= 3; i++) { Console.Write(i + " "); } Console.WriteLine("Done");

B. for (int i = 1; i <= 3; i++) { Console.WriteLine(i + " "); } Console.WriteLine("Done");

C. for (int i = 1; i <= 3; i++) { Console.Write(i); } Console.WriteLine("Done");

D. for (int i = 1; i <= 3; i++) { Console.WriteLine(i); } Console.Write("Done");

Solution

1. Step 1: Print numbers 1 to 3 on the same line with spaces

   Using Console.Write(i + " "); prints each number followed by a space without moving to a new line.

2. Step 2: Print "Done" on the next line

   Console.WriteLine("Done"); prints "Done" and moves to the next line.

3. Final Answer:

   for (int i = 1; i <= 3; i++) { Console.Write(i + " "); } Console.WriteLine("Done"); -> Option A

4. Quick Check:

   Write with space, then WriteLine for new line [OK]

Hint: Use Write with space, then WriteLine for next line [OK]

Common Mistakes:

• Using WriteLine inside loop causing multiple lines
• Not adding spaces between numbers
• Printing "Done" without newline