Java Quizzes

What is the correct syntax to output My first Java program?

How do you create a variable with a decimal value of 4.6 in Java?

(one or more answers)

Select the appropriate data type for this value: true

What is the output for "result"?

class ArithmeticOperators {
	public static void main(String[] args) {
		int a = 5;
		int b = 2;
		int c = 5;
		int result;

		result = ++a + --c * b;

		System.out.println(result);
	}
}

What is the output for result?

class ArithmeticOperators {
	public static void main(String[] args) {
		int a = 5;
		int b = 2;
		int result;

		result = --a * b++;

		System.out.println(result);
	}
}

Which operator can be used to decrement a value?

What is the output for result?

class ArithmeticModulo {
	public static void main(String[] args) {
		int a = 20;
		int b = 7;
		int c = 4;
		int result;

		result = a % b % c;

		System.out.println(result);
	}
}

What is the output for result?

class ArithmeticMixed {
	public static void main(String[] args) {
		int a = 10;
		int b = 20;
		int c = 5;
		int result;

		a = ++c;
		b = ++c;

		result = (a + b) % 2;

		System.out.println(result);
	}
}

Which operator can be used to check two values for equality?

What is the output for result?

class RelLogOperators {
	public static void main(String[] args) {
		int x = 5;
		int y = 6;
		int z = 6;
		boolean isSet = true;

		if (x < y && y >= z) {
			isSet = false;
		}

		System.out.println(isSet);
	}
}

What is the output for result?

class RelLogOperators {
	public static void main(String[] args) {
		int x = 3;
		int y = 6;
		int z = 4;
		boolean isSet = false;

		if (x < z && y >= z && x > z || isSet == false) {
			isSet = true;
		}

		System.out.println(isSet);
	}
}

What is the output for x?

class BitwiseOR {
	public static void main(String[] args) {
        int x, y, a = 10, b = 14, c = 2;
        x = a | b;
        System.out.println(x);
    }
}

What is the output for y?

class BitwiseExclusiveOR {
	public static void main(String[] args) {
        int x, y, a = 10, b = 14, c = 2;

		y = a ^ c;
		System.out.println(y);
    }
}

What is the output?

public class MethodRecursiveExample {
    static void fun(int val) {
        if (val == 20) {
            return;
        }

        System.out.print(val);
        fun(val + 2);
    }

    public static void main(String[] args) {
        fun(10);
    }
}

What is the output for result?

public class Quiz {
    public static int fun() {
        return 2.5 + 10.8;
    }
    
    public static void main(String[] args) {
        System.out.println(fun());
    }
}

Which is the correct way to write a comment in Java?

(one or more answers)

Which is the correct way to write a multi line comment in Java?

What is the output?

public class ControlStructuresQuiz {
	public static void main(String[] args) {
		int a = 4, b = 3;

		if (a >= b) {
			System.out.print(a);
		} else {
			System.out.print(b);
		}
	}
}

What is the output for c?

public class ControlStructuresQuiz {
	public static void main(String[] args) {
		int a = 5, b = 8, c = 0;

		while (c < 11) {
			if (a < b) {
				a++;
				c = c + 5;
			}
			else {
				c = c + 4;
			}
		}
		
		System.out.print(c);
	}
}

What is the output?

public class DataTypesExample {
    public static void main(String[] args) {
        int a = 0;
        double b = 0.0;
        
        System.out.print(a == b ? true : false);
    }
}

Which is the correct way to print a new line in Java?

Which is the correct way to print a horizontal tab line in Java?

What is the output for a?

public class OperatorQuiz extends Thread {
	public static void main(String[] args) {
		int a = 4, b = 10;

		while (b > a) {
			a++;
			if (a % 4 == 0) {
				break;
			}
		}
	
		System.out.print(a);
	}
}

What is the output for comp?

public class StringQuiz {
	public static void main(String[] args) {
		String s1 = "hello world";
		String s2 = "hello World";
		boolean comp = !s1.equals(s2);
		System.out.print(comp);
	}
}

Multiple inheritance is supported in Java?

What is the output?

public class MixedQuiz extends Thread {
	public static void main(String[] args) {
		int x = 4, y = 8, temp;

		temp = x;
		y++;
		temp--;
		x = y;
		y = temp;
	
		System.out.print(x + ", " + y);
	}
}

What is the output for x (how many loop passes)?

public class OperatorQuiz extends Thread {
	public static void main(String[] args) {
		double a = 20, b = 2;
		int x = 0;

		while (a > b) {
			a--;
			b = b + 4;
			x++;
		}
	
		System.out.print(x);
	}
}

What is the output?

public class MethodsQuiz {
	public static int add(int a, int b) {
		int result;
		result = a + b;
		return result;
	}

	public static void main(String[] args) {
		System.out.println(add(4, 2));
	}
}

What is the output?

public class MethodsQuiz {
	public static int add(int a, int b) {
		int result;
		result = a + b;
		return result;
	}

	public static void main(String[] args) {
		System.out.println(add(4.4, 2.5));
	}
}

What is the output?

public class Cube {
    static int add(int x = 5) {
        x = 12;
        return x + 1;
    }
    public static void main(String[] args) {
        System.out.print(add(10));
    }
}

What is the output for currentNumber?

public class ArraysQuiz {
	public static void main(String[] args) {
		int[] numbers = { 2, 7, 12, 9, 5, 18, 10, 5, 3, 17, 15 };
		int i = 0, currentNumber;

		currentNumber = numbers[0];

		for(i = 1; i < 10; i++) {
			if(currentNumber < numbers[i]) {
				currentNumber = numbers[i];
			}
		}

		System.out.print(currentNumber);
	}
}

What is the output?

public class ArraysQuiz {
	public static void main(String[] args) {
		int[][] myArray = new int[2][3];
 
		myArray[1][0] = 4;
		myArray[1][1] = 5;
		myArray[1][2] = 8;
		myArray[0][0] = 1;
		myArray[0][1] = 8;
		myArray[0][2] = 7;

		for (int i = 0; i < myArray.length; i++) {
			for (int j = 0; j < myArray[i].length; j++) {
				System.out.print(myArray[i][j]);
			}
		}
	}
}

What is the output?

import java.util.ArrayList;

public class Quiz {
    public static void main(String[] args) {
        ArrayList<Integer> myList = new ArrayList<Integer>();

        myList.add(5);
        myList.add(8);
        myList.clear();
        myList.add(3);
        myList.add(5);
        myList.add(9);

        System.out.println(myList.size());
    }
}

What is the output?

import java.util.ArrayList;
import java.util.Iterator;

public class Quiz {
    public static void main(String[] args) {
        ArrayList<Integer> myList = new ArrayList<Integer>();

        myList.add(1);
        myList.add(2);
        myList.add(2);
        myList.add(3);
        myList.add(4);
        myList.add(5);
        myList.add(6);
        myList.add(7);
        myList.remove(2);
        myList.remove(4);
        myList.remove(4);
        myList.remove(4);

        Iterator iter = myList.iterator();
        while (iter.hasNext()) {
            System.out.print(iter.next() + " ");
        }

        System.out.println(myList.size() + 1);
    }
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class SingleInheritanceQuiz {
	public static void main(String[] args) {
		Dog obj = new Dog();
		obj.printDog();
	}
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class SingleInheritanceQuiz {
	public static void main(String[] args) {
		Dog obj = new Dog();
		obj.printAnimal();
	}
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class SingleInheritanceQuiz {
	public static void main(String[] args) {
		Animal obj = new Animal();
		obj.printDog();
	}
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class Cat extends Dog {
	public void printCat() {
		System.out.println("This is a Cat");
	}
};

class MultilevelInheritanceQuiz {
	public static void main(String[] args) {
		Cat obj = new Cat();
		obj.printAnimal();
	}
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class Cat extends Dog {
	public void printCat() {
		System.out.println("This is a Cat");
	}
};

class MultilevelInheritanceQuiz {
	public static void main(String[] args) {
		Dog obj = new Cat();
		obj.printCat();
	}
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class Cat extends Animal {
	public void printCat() {
		System.out.println("This is a Cat");
	}
};

class helloworld {
	public static void main(String[] args) {
		Dog obj = new Cat();
		obj.printCat();
	}
}

What is the output?

class Animal {
	public void printAnimal() {
		System.out.println("This is an Animal");
	}
};

class Dog extends Animal {
	public void printDog() {
		System.out.println("This is a Dog");
	}
};

class Cat extends Animal {
	public void printCat() {
		System.out.println("This is a Cat");
	}
};

class helloworld {
	public static void main(String[] args) {
		Dog obj1 = new Dog();
		Cat obj = new Cat();
		obj.printAnimal();
		obj1.printDog();
	}
}

What is the output?

class StaticPolymorphism {
	void sum(int a, int b) {
		System.out.println(a + b);
	}

	void sum(double a, double b, double c) {
		System.out.println(a + b + c);
	}

	public static void main(String[] args) {
		StaticPolymorphism obj = new StaticPolymorphism();

		obj.sum(1, 2, 3);
		obj.sum(1.5, 2.5);
	}
}

What is the output?

void sum(int a, int b) {
    System.out.println(a + b);
}

void sum(double a, double b, double c) {
    System.out.println(a + b + c);
}

public static void main(String[] args) {
    helloworld obj = new helloworld();

    obj.sum(1.5, 2.5, 3.5);
    obj.sum(1, 2);
}

Is the output the same for a and c

class A {
	void print() {
		System.out.println("overridden method");
	}
}

class B extends A {
	void print() {
		System.out.println("overriding method1");
	}
}

class C extends A {
	void print() {
		System.out.println("overriding method2");
	}
}

public class helloworld {
	public static void main(String[] args) {
		A a = new C();
		C c = new C();

		a.print();
		c.print();
	}
}

Wat is the output for a?

class A {
	void print() {
		System.out.println("overridden method");
	}
}

class B extends A {
	void print() {
		System.out.println("overriding method1");
	}
}

class C extends A {
	void print() {
		System.out.println("overriding method2");
	}
}

public class helloworld {
	public static void main(String[] args) {
		A a = new B();

		a.print();
	}
}

What is the output?

public class MinMaxQuiz {
	public static void main(String[] args) {
		double min, max;
		int a = 12, b = 15;
	
		min = Math.min(a, b);
		max = Math.max(a, b);
	
		System.out.print(min + ", " + max);
	}
}

What is the output for rounded?

public class RoundingQuiz {
	public static void main(String[] args) {
		double value = 2.41245;

		// Round to nearest
		double rounded = Math.round(value);
	
		System.out.print(rounded);
	}
}

What is the output for rounded?

public class RoundingQuiz {
	public static void main(String[] args) {
		double value = 2.41245;

		// Round to nearest
		double rounded = Math.ceil(value);
	
		System.out.print(rounded);
	}
}

What is the output for rounded?

public class RoundingQuiz {
	public static void main(String[] args) {
		double value = 2.41245;

		// Round to nearest
		double rounded = Math.floor(value);
	
		System.out.print(rounded);
	}
}

What is the output for rounded?

public class RoundingQuiz {
	private static double roundDouble(double value, int decimalPoints) {
		double d = Math.pow(10, decimalPoints);
		return Math.round(value * d) / d;
	}
	public static void main(String[] args) {
		double value = 2.41245;

		// Round to nearest
		double rounded = roundDouble(value, 3);
	
		System.out.print(rounded);
	}
}

What is the output for rounded?

public class RoundingQuiz {
	public static void main(String[] args) {
		double value = 2.41855;

		System.out.println(String.format("%1.6f", value));
	}
}

What is the output for rounded?

public class MathFunctions {
    public static void main(String[] args) {
        double power;

        power = Math.pow(2, 5);

        System.out.println("Power: " + power);
    }
}

What is the output for rounded?

public class MathFunctions {
    public static void main(String[] args) {
        double sqrt;

        sqrt = Math.sqrt(169);

        System.out.println("Square: " + sqrt);
    }
}

What is the output for rounded?

public class MathFunctions {
	public static void main(String[] args) {
        double cubic;

        // Returns the cube root of a double value.
        cubic = Math.cbrt(216);

		System.out.println("Cubic: " + cubic);
	}
}

Java is a low level programming language!

Java is statically typed!
Which means the compiler or interpreter does the type checking once before the program runs or is compiled.

Java is a strongly-typed system!

Java supports inferred typing!

What is the output for sum?

public class AdvancedControlStructure {
    public static void main(String[] args) {
        int sum = 0;

        for (int i = 0, j = 2; i < 5 & j < 10; i = j - i, j++) {
            sum += j;
        }

        System.out.print(sum);
    }
}

What is the output?

public class MethodParametersExample {
    static int fun(int a, int b) {
        if (a == 0) {
            return b;
        } else {
            return a + fun(a - 1, b);
        }
    }

    public static void main(String[] args) {
        System.out.print(fun(2,5));
    }
}

What is the output?

class Test {
    private void privPrint() {
        System.out.print("A, ");
    }

    public void pubPrint() {
        System.out.print("B, ");
    }

    protected void protPrint() {
        System.out.print("C");
    }
}

class DataAbstraction {
    public static void main(String[] args) {
        Test t1 = new Test();

        t1.privPrint();
        t1.pubPrint();
        t1.protPrint();
    }
}

What is the output?

class Test {
    private void privPrint() {
        System.out.print("A, ");
    }

    public void pubPrint() {
        System.out.print("B, ");
    }

    protected void protPrint() {
        System.out.print("C");
    }
}

class DataAbstraction {
    public static void main(String[] args) {
        Test t1 = new Test();

        t1.pubPrint();
        t1.protPrint();
    }
}