Answer / akhil saxena

Immutable means which cant not be changed. whenever you call
a method though an instance of String class it will give you
the result as new String object. It wont change the existing
String object.

String class objects are made immutable so that if the
String is logically same,then more than one object can refer
the same single String in memory. in this way it also saves
memory.

Example: String a="ABC";
String b="ABC";

in above example JVM will create only one object with the
value "ABC" and both the reference variables a and b will
refer to the same. So it is saving memory.


If you need to change a String object very frequently, it is
not adviced to use a String object as it creates a new
object whenever you change its value. Its a best practice to
use StringBuffer. it is mutable.

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Answer / hari

Well it is immutable because of the memory concern. For
every new string if there is new object then it will take
lot of memory and if there is such requirement then there
is StringBuffer class provided.

Answer / mahi

Yes String cannot be modified because we can not append
another String to existing one.
Example:

1) String string=new String("abc");
2) String s2= string + "hai";

As shown in the above, 2nd line will create one new object
with the value "abchai" so it cannot be modified.

If the same thing if you do with StringBuffer class as
below we can modify

1) StringBuffer str=new StringBuffer("abc");
2) str.append("hai");
Here we can modify existing StringBuffer object - str

Answer / rohit kumawat

String class actually kept immutable by developers of "Sun
microsytems" because of you use it in desktop application
not for mobile application where memory is short & less to
work

Answer / syed

Since, return type of the string class cannot be altered
with substrings or any ammendments to it .

using equals method overriding which objects are compared?i.e same class objects or other class objects?Explain me.

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