Common Elements

Implement a method in Java named commonElements that finds the common elements between two integer arrays and returns them in a new array.

Requirements

• The method should be named commonElements.
• It must accept two parameters, both of which are arrays of integers (int[]).
• The return type of the method should be an array of integers (int[]).
• Ensure the method handles various scenarios including edge cases.

Edge Cases to Consider

1. No Common Elements: If there are no common elements between the two arrays, your method should return an empty array.
2. Identical Arrays: If both input arrays are identical, the method should return a complete copy of either array.

Examples

Example 1

int[] array1 = {1, 2, 3};
int[] array2 = {4, 5, 6};
int[] result = commonElements(array1, array2);
// result should be an empty array as there are no common elements

In this example, since there are no common elements between array1 and array2, the method returns an empty array.

Example 2

int[] array1 = {1, 2, 3, 4};
int[] array2 = {3, 4, 5, 6};
int[] result = commonElements(array1, array2);
// result should be {3, 4}

Here, the common elements between array1 and array2 are 3 and 4, so the method returns an array containing these two elements.

Challenges Information

Challenge 1: Validate Method Name and Return Type

• Objective: Ensure the Java method is correctly named commonElements and returns an array of integers.
• Requirements:
  • The method must be named exactly commonElements.
  • The return type must be an array of integers (int[]).
  • The method should accept two parameters, both of which are arrays of integers (int[]).

Challenge 2: Handling No Matching Elements

• Objective: Test the method's handling of scenarios with no common elements.
• Requirements:
  • The method should return an empty array (int[]) when the two input arrays have no common elements.
  • Consider edge cases such as empty input arrays or arrays with completely distinct elements.

Challenge 3: Identical Arrays Scenario

• Objective: Assess the method's functionality when both input arrays are identical.
• Requirements:
  • If both input arrays are the same, the method should return a complete copy of either array.
  • The output should be identical to the input arrays in content and order.

Challenge 4: Returning Common Elements

• Objective: Evaluate the method's core functionality to find and return common elements.
• Requirements:
  • The method must return an array containing all the common elements between the two input arrays.
  • The returned array should not contain any duplicates.
  • The order of elements in the returned array is not important.