数组

数组

数组声明创建

多维数组

package Jing.array;

public class ArrayDemo4 {
    public static void main(String[] args) {
        //[4][2]面向对象
        /*
        1，2  array[0]
        2，3  array[1]
        3，4  array[2]
        4，5  array[3]
         */
        int [][] array = {{1,2},{2,3},{3,4},{4,5}};
        for (int i = 0; i <array.length ; i++) {
            for (int j = 0; j <array[i].length ; j++) {
                System.out.println(array[i][j]);

            }
        }
    }
}

Arrays类

package Jing.array;

import java.util.Arrays;

public class ArraysDemo5 {
    public static void main(String[] args) {
        int [] a = {1,2,3,5,7,3,5,7,8,5,15916};
        System.out.println(a);//[I@14ae5a5
        //打印数组元素Arrays.toString
        System.out.println(Arrays.toString(a));//打印数组 [1, 2, 3, 5, 7, 3, 5, 7, 8, 5, 15916]

        printArray(a);//打印数组[1, 2, 3, 5, 7, 3, 5, 7, 8, 5, 15916]

        Arrays.sort(a);//数组排序：升序
        System.out.println(Arrays.toString(a));//[1, 2, 3, 3, 5, 5, 5, 7, 7, 8, 15916]

        Arrays.fill(a,2,4,0);
        System.out.println(Arrays.toString(a));//[1, 2, 0, 0, 5, 5, 5, 7, 7, 8, 15916]
    }
    public static void printArray(int [] a){
        for (int i = 0; i < a.length; i++) {
            if (i == 0){
                System.out.print("[");
            }if (i == a.length-1){
                System.out.print(a[i]+"]");
            }else {
                System.out.print(a[i]+", ");
            }

        }}
}