🔍 What is Java HashMap? Working Explained with Example Java HashMap is a powerful data structure from the Java Collections Framework that stores elements as key-value pairs. It allows fast access to data by leveraging hashing, making operations like insertion, lookup, and deletion highly efficient. HashMap is ideal when you need to associate unique identifiers […]
1. What are the advantages of using Redux with React? Redux centralizes application state in a single predictable store, making state flow explicit and easier to debug. It improves maintainability in large apps by decoupling UI from state logic, enables time-travel debugging, simplifies testing, and provides a clear place to apply middleware for logging, analytics, […]
1. How do you group strings by their length? Use Java Streams to bucket strings by length. This approach is concise, readable, and leverages the Collectors API for efficient grouping in a single pass. Map grouped = list.stream() .collect(Collectors.groupingBy(String::length)); Tip: For large lists, consider parallelStream() only when the operation is CPU-bound and the stream source […]
1. How do you filter strings that start with a specific letter? List<String> names = Arrays.asList(“Alice”, “Bob”, “Amanda”, “Brian”); List<String> filtered = names.stream() .filter(name -> name.startsWith(“A”)) .collect(Collectors.toList()); 2. How do you convert a list of strings to a map with string length as key? List<String> words = Arrays.asList(“Java”, “Stream”, “Lambda”); Map<Integer, String> map = words.stream() […]
1. What is a functional interface in Java 8? A functional interface defines exactly one abstract method and serves as a target for lambda expressions and method references. It may include default or static methods for reusable behavior and can be annotated with @FunctionalInterface to communicate intent and enable compiler checks. @FunctionalInterface interface MyFunc { […]