使用变量扩展辅助数组

const arr1 = [1, 2, 3];
const arr2 = [...arr1, 4, 5, 6];
console.log(arr2); // 输出：[1, 2, 3, 4, 5, 6]

arr1 = [1, 2, 3]
arr2 = arr1 + [4, 5, 6]
print(arr2) # 输出：[1, 2, 3, 4, 5, 6]

int[] arr1 = {1, 2, 3};
int[] arr2 = Arrays.copyOf(arr1, arr1.length + 3);
arr2[3] = 4;
arr2[4] = 5;
arr2[5] = 6;
System.out.println(Arrays.toString(arr2)); // 输出：[1, 2, 3, 4, 5, 6]

#include <iostream>
#include <vector>
using namespace std;

int main() {
    vector<int> arr1 = {1, 2, 3};
    vector<int> arr2 = arr1;
    arr2.push_back(4);
    arr2.push_back(5);
    arr2.push_back(6);
    for (int i : arr2) {
        cout << i << " ";
    }
    return 0;
}
// 输出：1 2 3 4 5 6