Nested conditional execution in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if-else with integer input

What is the output of the following C# code?

C Sharp (C#)

int x = 7;
if (x > 5)
{
    if (x < 10)
    {
        Console.WriteLine("A");
    }
    else
    {
        Console.WriteLine("B");
    }
}
else
{
    Console.WriteLine("C");
}

A No output

B B

C A

D C

💡 Hint

Check the conditions step by step starting from the outer if.

The variable x is 7, which is greater than 5, so the outer if is true. Then the inner if checks if x is less than 10, which is also true. So it prints "A".

❓ Predict Output

intermediate

Nested if-else with string comparison

What will be printed when this code runs?

C Sharp (C#)

string color = "red";
if (color == "blue")
{
    Console.WriteLine("Blue selected");
}
else
{
    if (color == "red")
    {
        Console.WriteLine("Red selected");
    }
    else
    {
        Console.WriteLine("Other color");
    }
}

A Red selected

B Blue selected

C Other color

D No output

💡 Hint

Check the value of the variable and the conditions carefully.

The variable color is "red", so the first if condition is false. The else block runs, and inside it the inner if checks if color is "red", which is true, so it prints "Red selected".

🔧 Debug

advanced

Identify the error in nested if-else code

What error will this C# code produce when compiled?

C Sharp (C#)

int n = 3;
if (n > 0)
    if (n < 5)
        Console.WriteLine("In range");
    else
        Console.WriteLine("Out of range");
else
    Console.WriteLine("Negative");
else
    Console.WriteLine("Zero");

A No error, prints "In range"

B Syntax error: else without matching if

C Runtime error: ambiguous else

D Syntax error: missing braces

💡 Hint

Look carefully at the placement of else statements and braces.

The code has two else statements at the same indentation level but only one if to match. This causes a syntax error: 'else' without a matching 'if'.

🚀 Application

advanced

Determine output of nested if with multiple conditions

What is the output of this code snippet?

C Sharp (C#)

int score = 85;
if (score >= 90)
{
    Console.WriteLine("Grade A");
}
else
{
    if (score >= 80)
    {
        Console.WriteLine("Grade B");
    }
    else
    {
        Console.WriteLine("Grade C");
    }
}

A Grade A

B No output

C Grade C

D Grade B

💡 Hint

Check the score against each condition carefully.

The score is 85, which is not >= 90, so the first if is false. The else block runs, and inside it the inner if checks if score >= 80, which is true, so it prints "Grade B".

🧠 Conceptual

expert

Understanding nested if-else flow

Consider this nested if-else structure:

if (A)
{
    if (B)
    {
        Action1;
    }
    else
    {
        Action2;
    }
}
else
{
    Action3;
}

Which statement is true about when Action2 executes?

A When A is true and B is false

B When A is false and B is true

C When A is false and B is false

D When B is true regardless of A

💡 Hint

Trace the conditions that lead to the else inside the first if.

Action2 is inside the else of the inner if (B). It runs only if A is true (outer if) and B is false (inner else).