java例程练习（String类对象相等问题）

public class Test {
public static void main(String[] args) {
String s1 = "hello";
String s2 = "world";
String s3 = "hello";

System.out.println(s1 == s3); //true
System.out.println(s1.equals(s3));//true

s1 = new String("hello");
s2 = new String("hello");
System.out.println(s1 == s2);//false
System.out.println(s1.equals(s2));//true

char c[] = {'s', 'u', 'n', ' ', 'j', 'a', 'v', 'a'};
String s4 = new String(c);
String s5 = new String(c, 4, 4);
System.out.println(s4);//sun java
System.out.println(s5);//java

}
}