1. What are the advantages of using Redux with React? It offers predictable state management, centralized store, and better debug-ability in large-scale apps. const store = createStore(rootReducer); 2. What is the role of the Provider component in Redux? It wraps your main component to pass the Redux store to all nested components. 3. How does […]

1. What is the Virtual DOM and how does React use it? The Virtual DOM is a lightweight copy of the real DOM. React uses it to detect changes by comparing the previous and current virtual DOM trees, then efficiently updates only the changed parts in the real DOM. 2. How does React’s reconciliation algorithm […]

1. How do you group strings by their length? Map<Integer, List<String>> grouped = list.stream()   .collect(Collectors.groupingBy(String::length)); 2. How do you group numbers by even and odd? Map<String, List<Integer>> grouped = numbers.stream()   .collect(Collectors.groupingBy(n -> n % 2 == 0 ? “Even” : “Odd”)); 3. How do you group employees by department? Map<String, List<Employee>> grouped = employees.stream()   .collect(Collectors.groupingBy(Employee::getDepartment)); […]

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 has exactly one abstract method. It can have multiple default or static methods. Example: Runnable, Comparator, or custom: @FunctionalInterfaceinterface MyFunc { void execute(); } 2. What is a lambda expression? A lambda expression provides a concise way to represent an anonymous function. Example: […]