This document discusses Java string classes and their differences. It provides an overview of strings in Java and describes the String, StringBuffer, and StringBuilder classes. The String class represents immutable strings and stores strings in a constant pool for efficiency. The StringBuffer and StringBuilder classes represent mutable strings but StringBuffer is synchronized for thread-safety while StringBuilder is not.

1. JAVA STRING
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2. PROJECT PROPOSAL
CONTENT
Overview
String class
String Constant pool
StringBuffer class
StringBuilder class

3. PROJECT PROPOSAL
OVERVIEW
A string is an object which shows the
sequence of characters. In Java, we can
create a string using three classes String,
StringBuffer, StringBuilder. All these classes
implement the CharSequence interface.

4. PROJECT PROPOSAL
STRING CLASS
String class is present in java.lang package.
String class provides a lot of methods for
performing the operations on the strings.
we can create String object using two ways:
By new keyword
By using String literal.

5. PROJECT PROPOSAL
STRING CLASS
If we create String Object through the new
keyword. JVM will create String object into
the Heap memory.
String str1=new String("Good Morning");
If we create String object using String literal,
JVM will store it into the String constant pool.
String str2="Good morning";

6. PROJECT PROPOSAL
CONSTANT POOL
String constant pool is a special memory area
which is a part of Heap memory. When we
create String object using String literal, JVM
first checks if String is already available in the
String constant pool. If it exists, JVM will
create only reference to it. If it does not exist,
JVM will create new String object and store it
in String constant pool.

7. PROJECT PROPOSAL
STRINGBUFFER CLASS
StringBuffer class is used to create a mutable
string. Mutable String is a string that can be
modified. It is synchronized class, i.e, Multiple
threads can't invoke the StringBuffer class
methods simultaneously.
StringBuffer str1= StringBuffer("Welcome");

8. PROJECT PROPOSAL
STRINGBUILDER CLASS
StringBuilder class is used to create mutable
strings. It is a non-synchronized class, i.e.,
Multiple threads can call methods of
StringBuilder simultaneously.
StringBuilder str2=new StringBuilder("Welcome");

9. PROJECT PROPOSAL
DIFFERENCES
The important difference between String,
StringBuffer, and StringBuilder class is:
String class is an immutable whereas
StringBuffer and StringBuilder classes are
mutable.
StringBuffer class is thread-safe while
StringBuilder class is not thread-safe class.

10. THANK YOU
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