Why conditional statements are needed in Java - Challenge Your Understanding

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Java code with conditional statements?

Look at the Java code below. What will it print when run?

Java

public class Main {
    public static void main(String[] args) {
        int temperature = 30;
        if (temperature > 25) {
            System.out.println("It's hot outside.");
        } else {
            System.out.println("It's cool outside.");
        }
    }
}

A It's cool outside.

B Compilation error

C It's hot outside.

D No output

💡 Hint

Check the value of temperature and the condition in the if statement.

The variable temperature is 30, which is greater than 25, so the if block runs and prints "It's hot outside." The else block is skipped.

🧠 Conceptual

intermediate

Why do we use conditional statements in programming?

Which of the following best explains why conditional statements are needed in programs?

A To allow the program to make decisions and choose different actions based on conditions.

B To repeat a set of instructions multiple times automatically.

C To store multiple values in a single variable.

D To define functions that can be reused.

💡 Hint

Think about how programs can behave differently depending on data or user input.

Conditional statements let programs decide what to do next based on conditions. This makes programs flexible and able to handle different situations.

❓ Predict Output

advanced

What is the output of this nested if-else Java code?

Analyze the Java code and select the exact output it produces.

Java

public class Main {
    public static void main(String[] args) {
        int score = 75;
        if (score >= 90) {
            System.out.println("Grade: A");
        } else if (score >= 80) {
            System.out.println("Grade: B");
        } else if (score >= 70) {
            System.out.println("Grade: C");
        } else {
            System.out.println("Grade: F");
        }
    }
}

A Grade: C

B Grade: B

C Grade: F

D Grade: A

💡 Hint

Check which condition the score 75 satisfies first.

The score 75 is not >= 90 or >= 80, but it is >= 70, so the program prints "Grade: C".

🔧 Debug

advanced

What error does this Java code produce?

This Java code tries to use an if statement but has a mistake. What error will it cause?

Java

public class Main {
    public static void main(String[] args) {
        int x = 10;
        if (x > 5) {
            System.out.println("x is greater than 5");
        }
    }
}

A TypeError: Cannot compare int and boolean

B RuntimeException: Null pointer exception

C No error, prints 'x is greater than 5'

D SyntaxError: Missing parentheses around condition

💡 Hint

Check the syntax of the if statement condition.

In Java, the condition in an if statement must be inside parentheses. Missing them causes a syntax error.

🚀 Application

expert

How many times will the message print?

Consider this Java code that uses a conditional inside a loop. How many times will it print "Number is even"?

Java

public class Main {
    public static void main(String[] args) {
        for (int i = 1; i <= 10; i++) {
            if (i % 2 == 0) {
                System.out.println("Number is even");
            }
        }
    }
}

A 10

B 5

C 0

D 1

💡 Hint

Count how many numbers from 1 to 10 are even.

The loop runs from 1 to 10. The condition checks if the number is even. Even numbers between 1 and 10 are 2,4,6,8,10 — 5 times.