How to Divide an Array List into Equal Segments

Question

What are the methods to split an ArrayList into equal parts?

ArrayList<String> arrayList = new ArrayList<>(Arrays.asList("A", "B", "C", "D", "E", "F"));

Answer

Splitting an ArrayList into equal segments allows for better data management and processing. In Java, you can achieve this by using loops, sublist methods, or external libraries like Guava.

public static List<List<String>> splitArrayList(List<String> list, int parts) {
    int size = list.size();
    int chunkSize = (int) Math.ceil((double) size / parts);
    List<List<String>> chunks = new ArrayList<>();
    for (int i = 0; i < size; i += chunkSize) {
        chunks.add(new ArrayList<>(list.subList(i, Math.min(size, i + chunkSize))));
    }
    return chunks;
}

Causes

  • Understanding the size of the ArrayList is crucial to determine the number of segments.
  • Not accounting for cases where the ArrayList size isn't perfectly divisible by the number of parts.

Solutions

  • Use a simple loop to create sublists based on calculated indices.
  • Utilize Java's `subList()` method for direct splitting of the ArrayList.
  • Consider using external libraries like Apache Commons Collections or Guava for more advanced splitting functionality.

Common Mistakes

Mistake: Not checking if the list is empty before splitting.

Solution: Always check if the list has elements to prevent IndexOutOfBoundsException.

Mistake: Failing to handle cases where the parts don't evenly divide the list.

Solution: Implement logic to manage remaining elements when the total size is not divisible by number of parts.

Helpers

  • split array list
  • Java ArrayList
  • divide list into parts
  • Java sublist method
  • Java ArrayList splitting

Related Questions

⦿How to Fix the Error 'No Enclosing Instance is Accessible' in Java

Learn how to resolve the Java error No enclosing instance is accessible with expert tips and code examples.

⦿What is the Purpose of Using Join in Embedded Jetty?

Discover the benefits and use cases for implementing join in Embedded Jetty for enhanced performance and functionality.

⦿How to Throw Exceptions with Mockito in Unit Tests?

Learn how to effectively throw exceptions using Mockito in unit tests with code examples and common mistakes to avoid.

⦿How to Convert a String to a Different Locale in Programming?

Learn how to convert strings to different locales in programming with practical examples and best practices for localization.

⦿How to Use a Controller Class in JavaFX Scene Builder 2

Learn how to effectively use a controller class in JavaFX Scene Builder 2 including coding examples and common mistakes to avoid.

⦿How to Resolve 'No Tests Found in TestClass: Did You Forget the @Test Annotation?' Error

Learn how to fix the No tests found in TestClass Did you forget the Test annotation error with expert debugging tips and solutions.

⦿How to Use the Java REPL Shell for Efficient Java Development

Learn how to effectively use the Java REPL ReadEvalPrint Loop shell for interactive Java programming and debugging.

⦿How to Fix XML Unmarshalling Error in Java 8: Handling SAXNotRecognizedException and IllegalStateException

Learn how to resolve Java 8 XML unmarshalling errors specifically SAXNotRecognizedException and IllegalStateException with expert solutions and tips.

⦿How to Fix Issues Running Eclipse on Ubuntu?

Troubleshooting common problems when running Eclipse on Ubuntu including configuration tips and solutions.

⦿How to Resolve the `java.io.IOException: No such file or directory` Error in Java?

Learn how to fix the java.io.IOException No such file or directory error in Java with stepbystep solutions and debugging tips.

© Copyright 2025 - CodingTechRoom.com