Java Developer Interviews

Java Developer Interview Questions

In your interview for a java developer position, be prepared to answer technical questions that test your understanding of Java basics. Interviewers may also ask open-ended questions to assess your coding and problem-solving abilities. Prepare for non-technical questions that focus on time management, interpersonal communication, and work ethic.

Top Java Developer Interview Questions & How to Answer

Question 1

Question #1: What is the difference between HashTable and HashMap in Java?

How to answer
How to answer: Interviewers use technical questions to assess your formal training and understanding of the Java programming language. Use your answer to demonstrate your communication skills. Even if you have been coding for some time, it can be helpful to review Java basics before your interview.
Question 2

Question #2: Write a program to determine if 243 is an Armstrong number.

How to answer
How to answer: Interviewers use open-ended questions to test your coding skills. This question allows the employer to assess your ability to solve a problem using a Java algorithm. Explain your thinking process as you use a code editor or whiteboard to solve the problem.
Question 3

Question #3: How do you produce quality code when you have several Java projects to complete at once?

How to answer
How to answer: Java developers often juggle multiple projects at the same time. Interviewers use questions such as this to test your time management and organizational skills. Employers are also trying to assess your commitment to quality work. If you have experience as a developer, include examples from your work history that demonstrate high-quality work and effective time management.

30,900 java developer interview questions shared by candidates

You are given an array of words (strings) and an integer k k k. Your task is to write a function that returns the k k k longest words from the array. If there are fewer than k k k words in the array, return all the words sorted by length in descending order. If there are ties in length, return the words in alphabetical order. Input: An array of strings words[] where each string consists of lowercase and uppercase letters only. An integer k k k (1 ≤ k k k ≤ 100). Output: An array of the k k k longest words, sorted by length (and alphabetically if lengths are equal). Example: plaintextInput: words = ["apple", "banana", "kiwi", "grape", "watermelon"], k = 3 Output: ["watermelon", "banana", "apple"] Input: words = ["cat", "bat", "rat"], k = 5 Output: ["bat", "cat", "rat"] Constraints: The output array should not exceed k k k elements. You may assume that the input will always have at least one word.
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Senior Java Developer

Interviewed at Apple

4.1
Apr 18, 2025

You are given an array of words (strings) and an integer k k k. Your task is to write a function that returns the k k k longest words from the array. If there are fewer than k k k words in the array, return all the words sorted by length in descending order. If there are ties in length, return the words in alphabetical order. Input: An array of strings words[] where each string consists of lowercase and uppercase letters only. An integer k k k (1 ≤ k k k ≤ 100). Output: An array of the k k k longest words, sorted by length (and alphabetically if lengths are equal). Example: plaintextInput: words = ["apple", "banana", "kiwi", "grape", "watermelon"], k = 3 Output: ["watermelon", "banana", "apple"] Input: words = ["cat", "bat", "rat"], k = 5 Output: ["bat", "cat", "rat"] Constraints: The output array should not exceed k k k elements. You may assume that the input will always have at least one word.

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