Heap memory in Java - Practice Problems & Coding Challenges

trophy

Challenge - 5 Problems

💻 code output

intermediate

What is the output of this Java code related to heap memory?

Consider the following Java code snippet. What will be printed to the console?

Java

public class HeapTest {
    public static void main(String[] args) {
        String a = new String("hello");
        String b = new String("hello");
        System.out.println(a == b);
        System.out.println(a.equals(b));
    }
}

A false\ntrue

B true\ntrue

C false\nfalse

D true\nfalse

🧠 conceptual

intermediate

Which statement about Java heap memory is true?

Choose the correct statement about Java heap memory.

A Heap memory is used to store local variables inside methods.

B Heap memory is shared among all threads and stores objects and arrays.

C Heap memory stores only primitive data types.

D Heap memory is automatically cleared when a method finishes execution.

🔧 debug

advanced

What error does this code cause related to heap memory?

Analyze the following Java code. What error will it cause when run?

Java

public class HeapOverflow {
    public static void main(String[] args) {
        int i = 0;
        while(true) {
            i++;
            int[] arr = new int[1000000];
            System.out.println("Iteration: " + i);
        }
    }
}

A OutOfMemoryError

B No error, infinite loop runs fine

C NullPointerException

D StackOverflowError

📝 syntax

advanced

Which option correctly declares an object stored in heap memory?

Which of the following Java code snippets correctly creates an object that will be stored in heap memory?

A int x = new int(5);

B String s = "hello";

C String s = new String("hello");

D int[] arr = 10;

🚀 application

expert

How many objects are created in heap memory after running this code?

Consider this Java code snippet. How many distinct objects are created in heap memory after it runs?

Java

public class ObjectCount {
    public static void main(String[] args) {
        String s1 = "test";
        String s2 = new String("test");
        String s3 = s2.intern();
        Integer i1 = 100;
        Integer i2 = new Integer(100);
    }
}

A 3

B 5

C 6

D 4