Example: Remove Duplicates from Array using For Loop in Java

// Remove Duplicates from Array using For Loop
import java.util.Arrays; // Required for Arrays.toString()

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Declare and initialize the array with duplicate elements
        int[] originalArray = {10, 20, 20, 30, 40, 10, 50, 60, 60, 70};
        System.out.println("Original array: " + Arrays.toString(originalArray));

        // Step 2: Create a temporary array to store unique elements
        // Initialize with the same size as original, as max unique elements can be same as original
        int[] tempArray = new int[originalArray.length];
        int uniqueCount = 0; // Counter for unique elements found

        // Step 3: Iterate through the original array
        for (int i = 0; i < originalArray.length; i++) {
            boolean isDuplicate = false; // Flag to check if current element is a duplicate

            // Step 4: For each element, check if it already exists in the tempArray
            // Iterate only up to 'uniqueCount' because beyond that, tempArray has default values (0 for int)
            for (int j = 0; j < uniqueCount; j++) {
                if (originalArray[i] == tempArray[j]) {
                    isDuplicate = true; // Element found, it's a duplicate
                    break; // No need to check further in tempArray
                }
            }

            // Step 5: If the element is not a duplicate, add it to tempArray
            if (!isDuplicate) {
                tempArray[uniqueCount] = originalArray[i];
                uniqueCount++; // Increment count of unique elements
            }
        }

        // Step 6: Create a new array of exact size 'uniqueCount' to store the final unique elements
        int[] uniqueArray = new int[uniqueCount];
        for (int i = 0; i < uniqueCount; i++) {
            uniqueArray[i] = tempArray[i]; // Copy elements from tempArray to uniqueArray
        }

        System.out.println("Array after removing duplicates: " + Arrays.toString(uniqueArray));
    }
}