Testdome Java Questions And Answers 【QUICK 2026】

Task:
Write a method that returns true if a string is a palindrome (case-insensitive, ignoring non-alphanumeric characters).

Example:
"A man, a plan, a canal: Panama" → true

public class DatabaseConnection 
    private static volatile DatabaseConnection instance;
private DatabaseConnection() 
    // private constructor
public static DatabaseConnection getInstance() 
    if (instance == null) 
        synchronized (DatabaseConnection.class) 
            if (instance == null) 
                instance = new DatabaseConnection();
return instance;
public void query(String sql) 
    // mock database query
    System.out.println("Executing: " + sql);

Key TestDome checks:

import java.util.*;
public class MergeNames 
public static String[] uniqueNames(String[] arr1, String[] arr2) 
// Guard against null inputs
if (arr1 == null && arr2 == null) return new String[0];
    Set<String> set = new TreeSet<>(); // TreeSet maintains sort order
    if (arr1 != null) 
        for (String s : arr1) 
            if (s != null) set.add(s); // Some tests inject null strings
if (arr2 != null) 
        for (String s : arr2) 
            if (s != null) set.add(s);
return set.toArray(new String[0]);

Why this works: TreeSet automatically sorts elements naturally (alphabetically). The explicit null checks prevent NullPointerException on hidden test #4.

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TestDome's Java assessment features automated work-sample tests that measure practical skills rather than just theory. A key feature for candidates is the availability of sample public questions, which allow for practice before a high-stakes interview. Popular Java Question Types

TestDome utilizes several formats to evaluate different skill levels:

Live Coding Challenges: Candidates solve problems like finding a "Two Sum" in an array or calculating discounted prices based on specific schemes. testdome java questions and answers

Refactoring Tasks: You might be asked to refactor existing code, such as an AlertService, by implementing interfaces and applying Inversion of Control principles.

Algorithmic Thinking: Common problems include Binary Search implementation (e.g., "Sorted Search") or working with HashSets (e.g., "Song" similarity).

Framework-Specific Tasks: Specialized tests cover Hibernate annotations, Spring Boot dependency injection, and Selenium web driver wait conditions.

MCQs & Fill-in-the-Blanks: These focus on core concepts like inheritance, class hierarchies (e.g., "Cache Casting"), and compilation errors. Key Feature: Automated Feedback & Proctering

Real-world Environment: The platform includes features like auto-completion for variables and functions to mimic a standard IDE.

Cheating Prevention: To ensure integrity, the system uses copy-paste protection, webcam proctoring, and IP tracking. Task: Write a method that returns true if

Detailed Scoring: Reports show exactly how long you took per question and provide a percentile ranking compared to other candidates. Practice Resources

You can find community-maintained solutions and practice sets on platforms like GitHub to prepare for these challenges:

jdegand/testdome-java-questions - Solutions for string manipulation and Spring AOP tasks.

HimashiNethinikaRodrigo/TestDomeJavaPractice - Multiple ways to pass specific test cases.

jadecubes/TESTDOME-Questions - Clean, learning-focused solutions with complexity analysis. Java Online Test | TestDome

You cannot import external libraries like Apache Commons, but you can use anything in java.util (HashMap, ArrayList, Collections, Optional, Streams). However, some companies disable streams due to performance overhead—stick to loops when possible. Key TestDome checks:

Prompt: A TrainComposition is built by attaching and detaching wagons from the left and right sides. Implement attachWagonFromLeft, attachWagonFromRight, detachWagonFromLeft, and detachWagonFromRight.

This tests your knowledge of Deque (double-ended queue). Using an ArrayList here fails the performance test for 1 million operations.