java数组添加元素

import java.util.ArrayList;
import java.util.Vector;
import java.util.Arrays;

public class ImoocStudent {

    public static void main(String args[]){

        int array[] = {2,5,4,-2,-3,-29,20};
        Arrays.sort(array);
        printArr("数组排序的结果为：",array);

        int index = Arrays.binarySearch(array,1);
        System.out.println("元素1在第" + index + "个位置(负数表示不存在)");

        int newIndex = -index -1;
        array = insertElement(array,1,newIndex);
        printArr("数组增加元素1",array);

    }


    private static void printArr(String message,int array[]){
        System.out.println(message + ":[length:" + array.length + "]");
        for(int i = 0;i < array.length;i++){
            if(i != 0)
                System.out.print(", ");
            System.out.print(array[i]);
        }

        System.out.println();
    }

    private static int[] insertElement(int original[],int element,int index){
        int length = original.length;
        int destination[] = new int[length + 1];
        System.arraycopy(original,0,destination,0,index);
        destination[index] = element;
        System.arraycopy(original,index,destination,index + 1,length - index);
        return destination;
    }
}

• https://www.runoob.com/java/arrays-insert.html