写一段程序来阐述数组简单的应用
package com.liaojianya.chapter1;
import java.util.Random;
/**
* This program demonstrates the use of array.
* @author LIAO JIANYA
* 2016年7月20日
*/
public class ArrayAssignment8_3
{
public static void main(String[] args)
{
Random rand = new Random();
int[] a = null;
int[] b = null;
a = new int[rand.nextInt(10) + 1];
b = a;
System.out.println("the length of array_a : " + a.length);
System.out.println("the length of array_b : " + b.length + "
");
for(int i = 0; i < a.length; i++)
{
a[i] = rand.nextInt(100);
System.out.print("a[" + i + "] = " + a[i] + " ");
System.out.println("b[" + i + "] = " + b[i]);
}
if(a.length == 1)
{
System.out.println("The array_a only has one element.
"
+ "So the max value of array_a is same as the min value!");
}
else
{
int max = a[0];
int min = a[0];
for(int i = 0; i < a.length; i++)
{
if(a[i] > max)
{
max = a[i];
}
else if(a[i] < min)
{
min = a[i];
}
}
System.out.println("
The max value of array_a is : " + max);
System.out.println("The min value of array_a is : " + min);
}
}
}
运行结果1：
the length of array_a : 1 the length of array_b : 1 a[0] = 70 b[0] = 70 The array_a only has one element. So the max value of array_a is same as the min value!
运行结果2：
the length of array_a : 7 the length of array_b : 7 a[0] = 39 b[0] = 39 a[1] = 90 b[1] = 90 a[2] = 49 b[2] = 49 a[3] = 35 b[3] = 35 a[4] = 33 b[4] = 33 a[5] = 12 b[5] = 12 a[6] = 75 b[6] = 75 The max value of array_a is : 90 The min value of array_a is : 12
分析：
1）代码行：b = a；表示将a数组的引用赋值给数组b，这时a和b是指向同一个数组对象。即“一个数组，两个名字”
2）创建一个Random类型的对象rand，此对象可以灵活的产生随机数，代码行a = new int[rand.nextInt(10)+1]; 在rand.nextInt（）后加1，可以避免出现0个元素数组。
若不加1，若随机到0，则会显示：
the length of array_a : 0 Exception in thread "main" the length of array_b : 0 java.lang.ArrayIndexOutOfBoundsException: 0 at com.liaojianya.chapter1.ArrayAssignment8_3.main(ArrayAssignment8_3.java:30)
3）将变量min与max初值设为数组的第一个元素后，再逐一的与数组中的各元素相比，比min小的就将该元素值赋给min存放，使得min中的值始终保持最小；同理，当该元素大于max时，就将该元素赋给max存放，使得max的值保持最大。