java - equals() and == for the class object -

i have enumeration emulation class. both objects in main p , pp passing == , equals test. both tests passed in case when

p = packettype.none;  pp = packettype.none;  

and both prints nothing in case

p = packettype.startofoperation;  pp = packettype.none; 

what invoked in method equals , operator ==? think == should not pas because must if object have same pointer. in other words should same object (and in our case not).

public class packettype {      string name = "9";      public static final packettype none = new packettype("9");     public static final packettype startofoperation = new packettype("1");      packettype(string name) {         this.name = name;     }      public string tostring() {         return name;     }      public static void main(string[] args) {          packettype p = packettype.none;          packettype pp = packettype.startofoperation;          if (p == pp) {             system.out.print("==");         }          if (p.equals(pp)) {             system.out.print("equals");         }     } } 

with objects == should used test whether references same instance of object. .equals(object o) should used check whether have equal value (however behaviour must implemented manually in custom objects, else defaults == behaviour).

a example of string people commonly make mistake of using == on .equals(object o) when trying check if strings equivalent.

string = "my string"; string b = "my string"; string c = a; //each of these should evaluate true a==c b!=c a.equals(b) b.equals(c) 

a full explanation of equals(object o) method can found here, can't find equivalent equality operator == (this one vague , refers primitives not objects).