package com.liaojianya.chapter1;

/**

 * This program demonstrates the difference between == and equals().

 * @author LIAO JIANYA

 * 2016年7月20日

 */

public class CompareObject

{

	public static void main(String[] args)

	{

		String s1 = new String("java");

		String s2 = new String("java");

		String s3 = s2;

		String s4 = new String("JAVA");

		//the use of ==

		if(s1 == s2)

		{

			System.out.println("s1和s2堆内存地址一样");

		}

		else

		{

			System.out.println("s1和s2堆内存地址不一样");

		}

		if(s2 == s3)

		{

			System.out.println("s2和s3堆内存地址一样");

		}

		else

		{

			System.out.println("s2和s3堆内存地址不一样");

		}

		//the use of equals()

		if(s1.equals(s2))

		{

			System.out.println("s1和s2内容一样");

		}

		else

		{

			System.out.println("s1和s2内容不一样");

		}

		if(s1.equals(s4))

		{

			System.out.println("s1和s4内容一样");

		}

		else

		{

			System.out.println("s1和s4内容不一样");

		}

	}

}

s1和s2堆内存地址不一样

s2和s3堆内存地址一样

s1和s2内容一样

s1和s4内容不一样