Ternary operator in Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested ternary operator

What is the output of the following Java code?

Java

public class Main {
    public static void main(String[] args) {
        int x = 5;
        String result = x > 0 ? (x < 10 ? "Small" : "Medium") : "Negative";
        System.out.println(result);
    }
}

A Compilation error

B Medium

C Negative

D Small

💡 Hint

Check the conditions in the nested ternary carefully.

The variable x is 5, which is greater than 0, so the first condition is true. Then it checks if x < 10, which is also true, so it returns "Small".

❓ Predict Output

intermediate

Ternary operator with boolean expressions

What will be printed by this Java program?

Java

public class Main {
    public static void main(String[] args) {
        boolean a = true;
        boolean b = false;
        String output = a ? (b ? "Both true" : "Only a true") : "a is false";
        System.out.println(output);
    }
}

A Only a true

B Both true

C a is false

D Compilation error

💡 Hint

Evaluate the conditions step by step.

Variable a is true, so the first condition is true. Then it checks b, which is false, so it returns "Only a true".

🔧 Debug

advanced

Identify the error in ternary usage

What error does this Java code produce?

Java

public class Main {
    public static void main(String[] args) {
        int x = 10;
        String result = x > 5 ? "Greater" : 5;
        System.out.println(result);
    }
}

A No error, prints "Greater"

B Type mismatch: cannot convert from int to String

C No error, prints "5"

D Syntax error: missing colon

💡 Hint

Check the types of both expressions in the ternary operator.

The ternary operator requires both expressions to be of compatible types. Here, one is String and the other is int, causing a type mismatch error.

🧠 Conceptual

advanced

Ternary operator evaluation order

Consider this Java code snippet:

int a = 3;
int b = 4;
int max = a > b ? a : b;

Which statement is true about how the ternary operator works here?

A Both a and b are evaluated before the ternary operator returns a value

B The ternary operator always evaluates both expressions regardless of the condition

C Only the expression corresponding to the true condition is evaluated

D The ternary operator evaluates neither expression and returns the condition's boolean value

💡 Hint

Think about short-circuit behavior in conditional expressions.

The ternary operator evaluates only the expression that matches the condition's result, not both.

❓ Predict Output

expert

Complex ternary operator with method calls

What is the output of this Java program?

Java

public class Main {
    static String check(int n) {
        return n % 2 == 0 ? "Even" : "Odd";
    }
    public static void main(String[] args) {
        int x = 7;
        String result = x > 5 ? check(x) : "Too small";
        System.out.println(result);
    }
}

A Odd

B Too small

C Compilation error

D Even

💡 Hint

Evaluate the condition and then the method call.

x is 7, which is greater than 5, so check(7) is called. 7 % 2 is 1, so it returns "Odd".