arraytest.java

孙鑫JAVA从入门到精通配套练习程序。所有程序都实际运行过

import java.util.Arrays;
//数组操作演示
class ArrTest
{
	public static void main(String[] args)
	{
	/*
		//数组拷贝（浅拷贝）
		Student[] num1 = new Student[]{new Student("zhangshan", 18),
																	 new Student("lisi", 20),
																	 new Student("wangwu", 30)};
		Student[] num2 = new Student[3];
		System.arraycopy(num1, 0, num2, 0, 3);
		for (int i=0; i<num2.length; i++)
		{
			System.out.println(num2[i]);
		}
		num2[2].name = "kkk";
		num2[2].num = 60;
		System.out.println(num1[2]);
	*/
		//数组排序
		Student[] num = new Student[]{new Student("zhangshan", 1),
																	new Student("lisi", 2),
																	new Student("wangwu", 3),
																	new Student("mybole", 3)};
		Arrays.sort(num);
		for (int i=0; i<num.length; i++)
		{
			System.out.println(num[i]);
		}
		int index = Arrays.binarySearch(num, new Student("lisi", 2));
		System.out.println(index);
		System.out.println(num[index]);
	}
}


class Student implements Comparable
{
	String name;
	int num;
	Student(String name, int num)
	{
		this.name = name;
		this.num = num;
	}
	public String toString()
	{
		return name + ", " +num;
	}
	public int compareTo(Object o)
	{
		Student s = (Student)o;
		int result;
		result = num > s.num ? 1 : (num == s.num ? 0 : -1);
		if (0 == result)
		{
			result = name.compareTo(s.name);
		}
		return result;
	} 
}