Created: 2023-08-26 10:13
Status: #concept
Subject: Programming
Tags: Java Java Package

java.util

List of Commonly-used Packages

1. java.util.Scanner

   • parse primitive Java Data Types and String Literals using Regular Expressions.

2. java.util.ArrayList

   • a Java Generic Type list data structure imitating a Linked List.

3. java.util.HashMap

   • a HashMap<T1, T2> helper class for Hashmaps.

4. java.util.Random

   • allows us to do randomGenerator.nextInt(int bound).

5. java.util.Arrays

   • contains Arrays static class methods.

6. java.util.Collectors

   • contains Collectors.toList() and Collectors.toCollectionnew static class methods.

7. java.util.Collections

   • contains static helper methods to manipulate anything that implements Collections.
   • Collections.sort(ArrayList<T> list) sorts an ArrayList.

8. java.util.Stream

   • provides Java Interface definitions for .stream() methods to let us process aggregate data with Java Lambda Expressions.

9. java.util.Comparable

   • allows us to implements Comparable<T> to define a .compareTo(T obj) method for comparison with java.util.Comparator functions.

10. java.lang.StringBuilder

    • optimizes string concatenation with .append(String).

References

• java.util (Java SE 17 & JDK 17)