多维数组、数字存储表格数据、使用JavaBean和一维数组保存表格数据

多维数组

多维数组可以看成以数组为元素的数组，可以有二维、三维甚至是多维数组。

二维数组声明：

/*
 * 二维数组的声明
 */
package cn.wu.array;

import java.util.Arrays;

public class Test10 {
	public static void main(String[]args){
//		java众多数组的声明是按照低维到高维的顺序进行；
		int[][] a = new int[3][];//定义数组一维的长度
		a[0] = new int[2]; //定义数组二维的长度
		a[2] = new int[3]; 
		a[1] = new int[4]; 
//		int a[][] = new int[][3]是非法的；
		System.out.println(Arrays.deepToString(a));
//		Arrays.deepToString()方法是打印多维数组
	}

}

二维数组静态初始化；

/*
 * 二维数组的静态初始化
 */
package cn.wu.array;

import java.util.Arrays;

public class Test11 {
	public static void main(String[]args){
		int[][] a = {{1,2,3},{3,4},{3,5,6,7}};
		System.out.println(Arrays.deepToString(a));
		System.out.println(a[2][3]);
	}

}

二维数组动态初始化：

* 二维数组的动态初始化
 */
package cn.wu.array;

import java.util.Arrays;

public class Test12 {
	public static void main(String[]args){
		int[][] a = new int[3][];
//		a[0] = {1,2,5}错误未声明类型就初始化
		a[0] = new int[]{1,2};
		a[1] = new int[]{2,2};
		a[2] = new int[ ]{2,2,3,4};
		System.out.println(a[2][3]);
		System.out.println(Arrays.toString(a[0]));
		System.out.println(Arrays.toString(a[1]));
		System.out.println(Arrays.toString(a[2]));
		System.out.println(Arrays.deepToString(a));
	}

}

获取数组的长度

/*
 * 获取数组的长度
 */
package cn.wu.array;

import java.util.Arrays;

public class Test13 {
	public static void main(String[] args) {
		String[][] s = new String[3][];
		s[0] = new String[]{"蝙蝠侠","蜘蛛侠","闪电侠"};
		s[1] = new String[]{"小丑","绿魔","逆闪电"};
		s[2] = new String[]{"丧钟","死侍","惩罚者"};
		System.out.println(Arrays.deepToString(s));
		System.out.println(s.length);
		System.out.println(s[0].length);
	}

}

数字存储表格数据

使用二维数组保存表格数据：

* 使用二维数组保存表格数据
 */
package cn.wu.array;

import java.util.Arrays;

public class Test14 {
	public static void main(String[] args) {
		Object[] a1 = {1001,36,"蝙蝠侠","灵魂人物","2021-4-31"}; 
		Object[] a2 = {1002,35,"超人","最强战力","2021-5-1"};
		Object[] a3 = {1003,90,"神奇女侠","神秘侧战力","2021-5-2"};
		Object[] a4 = {1004,25,"闪电侠","吉祥物祭品","2021-5-3"};
		
		Object[][] jl = new Object[4][];
		jl[0] = a1;
		jl[1] = a2;
		jl[2] = a3;
		jl[3] = a4;
		System.out.println(Arrays.toString(jl[0]));
		System.out.println(Arrays.toString(jl[1]));
		System.out.println(Arrays.toString(jl[2]));
		System.out.println(Arrays.toString(jl[3]));
		
	}

}

使用JavaBean和一维数组保存表格数据：

* 使用javabean和一维数组保存表格数据信息
 */
package cn.wu.array;

public class Test15 {
	public static void main(String[]args){
		Jl[] jls = { new Jl(1001,36,"蝙蝠侠","灵魂人物","2021-4-31"),
		             new Jl(1002,35,"超人","最强战力","2021-5-1"),
		             new Jl(1003,90,"神奇女侠","神秘侧战力","2021-5-2"),
					 new Jl(1004,25,"闪电侠","吉祥物祭品","2021-5-3")
		};
		for(Jl h:jls){
			System.out.println(h);
		}
	}

}
/**
 * @author WY
 *
 */
class Jl{
	private int id;
	private int age;
	private String name;
	private String job;
	private String hiredate;
	public Jl(int id, int age, String name, //有参构造器
			String job, String hiredate) {
		super();
		this.id = id;
		this.age = age;
		this.name = name;
		this.job = job;
		this.hiredate = hiredate;
	}
	public Jl(){};//无参构造器
	@Override
	public String toString() {//重写toString方法
		return "Jl [id=" + id + ", age=" + age + ", name=" + name + ", job=" + job + ", hiredate=" + hiredate + "]";
	}
	
//	get（）和set（）方法访问域变量，获取和设置私有属性；
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getJob() {
		return job;
	}
	public void setJob(String job) {
		this.job = job;
	}
	public String getHiredate() {
		return hiredate;
	}
	public void setHiredate(String hiredate) {
		this.hiredate = hiredate;
	}
	
}