Ans this pls

Question

String s1="abc";
String s2="abc";
Sop(s1==s1);
Sop(s1.equals(s2));

output is true true

String str = new String("hai");
String s= new String("hai");
System.out.println(str==s);
System.out.println(str.equals(s));

output is false true

what is the difference between two programs ?

Answer 1

c lover, String is actually a class that is included in java.lang package

Answer 2

There's an optimization the compiler makes called the String Constant Pool.
Any Strings with Constant literals are placed here.
In your example,
String s1 = "abc";

The String literal "abc" will be placed in the pool.

Everytime the literal "abc" is used, instead of creating a new object the string will point to the memory location of the string in the pool.
So,
String a = "abc";
String b = "abc";

These variables point to the EXACT same objects.
It's like writing:
Object d = new Object();
Object e = d;

As Nikhil Sharma's said, == compares the value of the memory location of objects. As Donna said, a String is a class.
So,
== will result in true; they are the same obects.

But, there's a catch.
When using the new keyword a String will not be interned unless done manually. In other words, a new String will be created instead of checking the SCP for the same string values.
String a = new String("b");
String b = new String("b");

So, these are different objects.
See:
https://code.sololearn.com/cGquk1UvwLrJ/?ref

Answer 3

https://www.sololearn.com/learn/Java/2178/?ref=app

Answer 4

== checks whether the references points to the same object or not whereas equals method checks whether the value of the obejcts referenced by the variables are same or not.

Answer 5

Donna
Careful, == does not check if two objects are from the same class.

Answer 6

Donna but I created str and s in same class not n different class

Answer 7

class Demo
{
public static void main (String[] args) throws java.lang.Exception
{
String str = new String("hai");
String s= new String("hai");
System.out.println(str==s);
System.out.println(str.equals(s));
}
}

see Dona

Answer 8

yes Donna I created two object of same string class na...

Answer 9

I understood Donna ...they r different class...thank you so much

Answer 10

thank you donna

Answer 11

yes nikil but u didn't understand my question

Answer 12

what u mean by class ....then WT is demo class??

Answer 13

here string is keyword not class rite

Answer 14

ok fine then I created two object of same string class right