Category: Java8

Top Java8 Stream Grouping by Interview Questions with examples

  • June 20, 2025
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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 […]

Top Java8 Streams Interview Questions

  • June 20, 2025
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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() […]