Common ways to add elements to Java arrays

Common methods for adding elements to Java arrays require specific code examples

In Java, arrays are a common data structure that can store multiple elements of the same type. element. In actual development, we often need to add new elements to the array. This article will introduce common methods of adding elements to arrays in Java and provide specific code examples.

1. Use a loop to create a new array

A simple way is to create a new array, copy the elements of the old array into the new array, and add the new elements . The code example is as follows:

// 原始数组
int[] oldArray = { 1, 2, 3, 4, 5 };
// 新元素
int newElement = 6;

// 新数组长度为原数组长度加1
int[] newArray = new int[oldArray.length + 1];

// 复制旧数组到新数组
for (int i = 0; i < oldArray.length; i++) {
  newArray[i] = oldArray[i];
}

// 添加新元素到新数组的末尾
newArray[newArray.length - 1] = newElement;

// 打印新数组
for (int element : newArray) {
  System.out.println(element);
}

2. Using the ArrayList class

In Java, ArrayList is a dynamic array that can easily add, delete and modify elements. We can use ArrayList to implement the addition operation of the array. The code example is as follows:

import java.util.ArrayList;

// 创建ArrayList
ArrayList<Integer> list = new ArrayList<>();

// 添加元素
list.add(1);
list.add(2);
list.add(3);

// 打印ArrayList
for (int element : list) {
  System.out.println(element);
}

3. Use Arrays.copyOf()

Arrays.copyOf() method to copy an array to a new array and specify the new array length. We can use this method to add new elements. The code examples are as follows:

import java.util.Arrays;

// 原始数组
int[] oldArray = { 1, 2, 3, 4, 5 };
// 新元素
int newElement = 6;

// 新数组长度为原数组长度加1
int[] newArray = Arrays.copyOf(oldArray, oldArray.length + 1);

// 添加新元素到新数组的末尾
newArray[newArray.length - 1] = newElement;

// 打印新数组
for (int element : newArray) {
  System.out.println(element);
}

Summary:

This article introduces several common methods of adding elements to arrays in Java and provides specific code examples. We can easily add new elements to the array by looping to create new arrays, using the ArrayList class, and using the Arrays.copyOf() method. Based on actual needs and scenarios, we can choose a suitable method to perform array operations.

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