public class Test {
public static void main(String[] args) {
String str1="good";
System.out.println(str1=="good");
System.out.println(str1.equals("good"));
//==============================
String str2="goodjob";
System.out.println(str2.substring(0, 4)=="good");
System.out.println(str2.substring(0, 4).equals("good"));
}
}
true true false true