String

String:
A String in Java is a sequence of characters. It is one of the most commonly used objects in Java programs because it represents text.

Keypoints:
String is a class:
In Java, String is not a primitive data type but a class in the java.lang package.
It means that String objects have methods you can use to manipulate the text.

Immutable:
Once a String object is created, it cannot be changed.
Any modification like concatenation or replacement creates a new String object.

String Pool:
Java optimizes memory by storing strings in a special area called the String Pool.
Strings with the same content can refer to the same object in memory.

How to create a String?
1)Using string literal (stored in String Pool)
String s1 = "Hello";

2)Using 'new' keyword (creates a new object in heap memory)
String s2 = new String("Hello")

Advantages of Strings
Immutable:
Once created, the string cannot be changed.
Helps avoid accidental modifications.
Safer in multi-threaded environments.

String Pool for Memory Efficiency:
Reduces memory usage by reusing existing strings.

Rich API Methods:
Methods like length(), substring(), replace(), toLowerCase(), etc., make text processing easy.

Thread-Safe:
Immutable nature makes it safe to use in multiple threads.

Easy to Use:
Simple syntax with intuitive operations.

Disadvantages of Strings
Memory Overhead:
Every change creates a new object, leading to more memory consumption.

Performance Cost:
Frequent modifications (e.g., in loops) result in many temporary objects, slowing down the program.

Garbage Collection Pressure:
Repeated creation of new strings can increase workload for the garbage collector.

Not Suitable for Heavy Modification:
For scenarios where text is constantly changing, alternatives like StringBuilder or StringBuffer are better.