10. String and Operators.

 String

Strings in Java are a crucial aspect of programming, as they allow for the manipulation and handling of text. Here’s a detailed explanation of strings, their characteristics, and how they can be created and used in Java.

Characteristics of Strings in Java

1. String Class:

   • String is a predefined class in Java, derived from the java.Lang package.
   • It is a non-primitive data type because it is a class.
   • A String is a collection of characters enclosed within double quotes (" ").

2. Immutability:

• Strings in Java are immutable, meaning once a String object is created, its value cannot be changed.

Creating Strings in Java

There are two main ways to create a string in Java:

       1. Using String Literals:

• When a string is created using string literals, it is stored in the String Constant Pool (SCP)                                                                                                                        
• Example - String a = "Hello" ;

      2. Using the new Keyword:

• When a string is created using the new keyword, it is stored in the heap area            
• Example - String b = new String("Hello") ;

Different Classes for Creating Strings

• The String class is used to create immutable strings.

In Java, we can create and manipulate strings using three different classes:

1. String:

2. String Buffer:

   • The String Buffer class is used to create mutable strings (strings that can be changed).
   • It is synchronized, meaning it is thread safe.

3. StringBuilder:

   • The StringBuilder class is also used to create mutable strings.
   • It is not synchronized, meaning it is not thread-safe but offers better performance in a single-threaded environment.

Example of string 

           class Example

                  {

                          public static void main(String[] args)

                                  {

                                          String a = "Hello";          // Will print Hello

                                          String b = "H";              // H

                                          String c = 10;            // Incompatible datatype, will cause an error

                                          String d = true;          // Incompatible datatype, will cause an error

                                          String e = 'A';           // Incompatible datatype, will cause an error

                                          String f = 1.1;           // Incompatible datatype, will cause an error

                                          String g = "Hello" + 1;      // This will concatenate

                                          System.out.println(a);       // Output: Hello

                                          System.out.println(b);       // Output: H

                                          System.out.println(g);       // Output: Hello1

                                  }

                    }

Operators  

Operators are symbols that are used to perform operations on variables and values (operands). They are a fundamental part of any programming language.

Operators are of two types -

1) Based on type of Operation it Perform 

• Arithmetic Operators
• Relational Operators
• Logical Operators
• Bitwise Operators
• Assignment Operators
• Conditional Operator
• Compound Assignment Operator
• Increment and Decrement Operator
• Miscellaneous Operator

2) Based on Number Of Operands

• Unary Operators
• Binary Operators
• Ternary Operators