regarding operators

[rameshbabu yarlagadda]

what is the Difference between == operator and .equals(),=.
Where can we use above things.

[Acoyani Garrido Sandoval]

As far as I know, the == works with everything but strings. That's why you have the .equals(Some string) method: because this way, you can see if a string is the same as another one.

I don't know if you can use this same method with other data types though. However, I'd rather use the plain ol' ==, because that means "compare", while the .equals() means "go call a function that compares and returns a boolean value", which is of course much, much less efficient.
[ September 09, 2007: Message edited by: Acoyani Garrido Sandoval ]

[Em Aiy]

if you want to compare two primitive types then you'll use == operator and for all other objects (String, vector, set etc) you'll use .equal.

.equal method compare the contents of the contained by the object. if you use == operator on two objects (say string) it'll compare the memory location not the string itself.

just look at the following code

String a ="a";
String b = a;
if (a == b)
    System.out.println("this will be printed");

in this case the if condition will work

String a ="a";
String b = "b";
if (a == b)
    System.out.println("this will not be printed");
else
    System.out.println(" this will be printed");

now look at the following code .. and test yourself

String a = "a";
String b = "a";
if (a==b){
    System.out.println("this will be printed .. your job to find why");
}

[code]
String a ="a";
String b = new String("a");
if (a==b){
System.out.println("the else statement will be printed, find out why");
}