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Java Collection, ArrayList Exercises: Join two array lists

Java Collection, ArrayList Exercises: Exercise-15 with Solution

Write a Java program to join two array lists.

Pictorial Presentation:

Java Collection, ArrayList Exercises: Join two array lists

Sample Solution:-

Java Code:

import java.util.ArrayList;
import java.util.Collections;
  public class Exercise15 {
  public static void main(String[] args) {
   ArrayList<String> c1= new ArrayList<String>();
          c1.add("Red");
          c1.add("Green");
          c1.add("Black");
          c1.add("White");
          c1.add("Pink");
          System.out.println("List of first array: " + c1);
          ArrayList<String> c2= new ArrayList<String>();
          c2.add("Red");
          c2.add("Green");
          c2.add("Black");
          c2.add("Pink");
          System.out.println("List of second array: " + c2);
         
      // Let join above two list
        ArrayList<String> a = new ArrayList<String>();
        a.addAll(c1);
        a.addAll(c2);
        System.out.println("New array: " + a);
        

     }
}

Sample Output:

List of first array: [Red, Green, Black, White, Pink]                  
List of second array: [Red, Green, Black, Pink]                        
New array: [Red, Green, Black, White, Pink, Red, Green, Black, Pink]

Flowchart:

Flowchart: Join two array lists.

Java Code Editor:

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Previous: Swap two elements in an array list.
Next: Clone an array list to another array list.

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Java: Tips of the Day

getEnumMap

Converts to enum to Map where key is the name and value is Enum itself. 

public static <E extends Enum<E>> Map<String, E> getEnumMap(final Class<E> enumClass) {
    return Arrays.stream(enumClass.getEnumConstants())
            .collect(Collectors.toMap(Enum::name, Function.identity()));
}

Ref: https://bit.ly/3xXcFZt