String s1 = "Welcome to java"; String s2 = new String("Welcome to java"); //因为之前已经创立了s1这一个物理地址,所以系统检测的时候首选的是s1,故s1 == s3. String s3 = "Welcome to java"; String s4 = "welcome to java"; String s5 = "Welcome"; String s6 = " to"; String s7 = ...