为什么第一个输出是Equal,而第二个是NotEqualpublicclassTestString{Stringst=newString("Hello");publicstaticvoidmain(Stringarg[]){TestStringtest=newTestString();TestString1test1=newTestString1();if(test1.st1==test1.st2)

Question

为什么第一个输出是Equal,而第二个是Not Equal
public class TestString
{
String st= new String("Hello");
public static void main(String arg[])
{
TestString test = new TestString();
TestString1 test1 = new TestString1();
if(test1.st1 == test1.st2)
System.out.println("Equal");
else
System.out.println("Not Equal");
if(test.st == test1.st1)
System.out.println("Equal");
else
System.out.println("Not Equal");
System.out.println(test.st+"\n"+test1.st1+"\n"+test1.st2);
}
}
class TestString1
{
String st1 = "Hello";
String st2 = "Hello";
}

Answer 1

java中“==”比较的是引用变量的地址是否相等,可以用equals方法来比较,equals比较的是内容.