Learn how to efficiently remove duplicate elements from Java arrays

As a popular programming language, Java’s array operations are one of the common tasks in programmers’ daily work. When processing arrays, we often encounter situations where we need to deduplicate the array to ensure that the array does not contain duplicate elements. This article will introduce several fast and concise Java array deduplication methods and provide specific code examples.

Method 1: Use HashSet

HashSet is a collection type in Java. Its characteristic is that it does not allow duplicate elements. We can use this feature of HashSet to deduplicate arrays. The specific steps are as follows:

public static int[] removeDuplicates(int[] array) {
    HashSet<Integer> set = new HashSet<>();
    for (int value : array) {
        set.add(value);
    }
    int[] result = new int[set.size()];
    int index = 0;
    for (int value : set) {
        result[index++] = value;
    }
    return result;
}

Method 2: Use Stream
Java 8 introduced the Stream API, which provides a way to operate collections in a streaming manner. We can use the distinct() method of Stream to quickly deduplicate arrays. The example is as follows:

public static int[] removeDuplicates(int[] array) {
    return Arrays.stream(array).distinct().toArray();
}

Method 3: Use loop traversal
In addition to using collections and Streams to deduplicate arrays, we can also use basic Loop traversal method to achieve array deduplication. The specific steps are as follows:

public static int[] removeDuplicates(int[] array) {
    int length = array.length;
    int count = 0;
    for (int i = 0; i < length; i++) {
        boolean isDuplicate = false;
        for (int j = i + 1; j < length; j++) {
            if (array[i] == array[j]) {
                isDuplicate = true;
                break;
            }
        }
        if (!isDuplicate) {
            array[count++] = array[i];
        }
    }
    int[] result = new int[count];
    System.arraycopy(array, 0, result, 0, count);
    return result;
}

Summary

This article introduces three commonly used Java array deduplication methods and provides specific code examples. Whether using HashSet, Stream or basic loop traversal, array deduplication operations can be completed quickly and effectively. In actual work, you can choose an appropriate method to handle the need for array deduplication according to the specific situation, thereby improving the efficiency and readability of the code.

The above is the detailed content of Learn how to efficiently remove duplicate elements from Java arrays. For more information, please follow other related articles on the PHP Chinese website!