java两个数组元素相乘 java两个数组拼接

//这是用第三种方式调用的
import java.util.Arrays;

public class Day09Task01 {
    public static void main(String[] args) {
        int[] arr = {4, 6, 7};
        int[] arr2 = {34, 67, 98, 3};
        int[] newArr = new int[arr.length + arr2.length];
        //第一种
        for (int i =0;i<arr.length;i++){
            newArr[i] = arr[i];
        }
        //将arr2添加到新数组中
        for (int j=0;j<arr2.length;j++){
            newArr[arr.length+j] = arr2[j];
        }
        for (int k=0;k<newArr.length;k++){
            System.out.print(newArr[k]+" ");
        }
        //第二种
//        System.arraycopy(arr, 0, newArr, 0, arr.length);
//        System.arraycopy(arr2, 0, newArr, arr.length, arr2.length);
//        for (int i = 0; i < newArr.length; i++) {
//            System.out.print(newArr[i] + " ");
        //第三种
//        int i = 0;
//        for (int c:arr){
//            newArr[i] = c;
//            i++;
//        }
//        for (int c:arr2){
//            newArr[i] = c;
//            i++;
//        }
//        System.out.print(Arrays.toString(newArr));
    }
}