Primitive vs reference storage in Java - Practice Questions

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Challenge - 5 Problems

💻 code output

intermediate

Output of primitive and reference variable changes

What is the output of the following Java code?

Java

public class Test {
    public static void main(String[] args) {
        int a = 5;
        int b = a;
        b = 10;
        System.out.println("a = " + a);
        System.out.println("b = " + b);
    }
}

A a = 5\nb = 10

B a = 5\nb = 5

C a = 10\nb = 10

D a = 10\nb = 5

💻 code output

intermediate

Output when modifying an object reference

What is the output of this Java code?

Java

public class Test {
    public static void main(String[] args) {
        int[] arr1 = {1, 2, 3};
        int[] arr2 = arr1;
        arr2[0] = 10;
        System.out.println(arr1[0]);
    }
}

A 1

B 10

C Compilation error

D 0

💻 code output

advanced

Effect of reassigning object references

What is the output of this Java code?

Java

public class Test {
    public static void main(String[] args) {
        StringBuilder sb1 = new StringBuilder("Hello");
        StringBuilder sb2 = sb1;
        sb2.append(" World");
        sb2 = new StringBuilder("New");
        System.out.println(sb1.toString());
    }
}

A New

B Hello

C Hello World

D Compilation error

💻 code output

advanced

Output when passing primitives and objects to methods

What is the output of this Java code?

Java

public class Test {
    public static void main(String[] args) {
        int x = 5;
        StringBuilder sb = new StringBuilder("Hi");
        modify(x, sb);
        System.out.println(x + " " + sb.toString());
    }
    static void modify(int a, StringBuilder b) {
        a = 10;
        b.append(" there");
    }
}

A 5 Hi

B 10 Hi there

C 10 Hi

D 5 Hi there

🧠 conceptual

expert

Understanding memory behavior of primitives and references

Which statement best describes how Java stores primitive types and reference types in memory?

A Primitive variables store the actual data value; reference variables store the memory address of the object.

B Primitive variables store the memory address of the object; reference variables store the actual data value.

C Both primitive and reference variables store actual data values directly in the stack memory.

D Both primitive and reference variables store memory addresses pointing to objects in the heap.