#34 What is String in JAVA | Skyhighes | Lecture 34

11 months ago
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Here's a comprehensive explanation of Strings in Java:

What are Strings?

Strings are sequences of characters used to represent text data in Java.
They are objects, not primitive data types like int or char.
The String class provides methods for manipulating, comparing, and transforming strings.
Key Characteristics:

Immutable: Once a string is created, its contents cannot be changed. Any operation that seems to modify a string actually creates a new string object.
Sequence of characters: Each character in a string has an index, starting from 0.
Unicode: Java strings support the Unicode character set, enabling representation of characters from various languages and symbols.
Creating Strings:

Using double quotes:
Java
String name = "Bard";
String greeting = "Hello, world!";
Use code with caution. Learn more
Using the new keyword (less common):
Java
String message = new String("Welcome!");
Use code with caution. Learn more
Using string literals (Java 10+):
Java
String poem = """Roses are red,
Violets are blue,
This is a multi-line string.""";
Use code with caution. Learn more
Common String Operations:

Concatenation: + operator
Accessing characters: charAt(index)
Length: length()
Finding substrings: indexOf(), lastIndexOf()
Comparing strings: ==, compareTo()
Converting to uppercase/lowercase: toUpperCase(), toLowerCase()
Trimming whitespace: trim()
Splitting into substrings: split()
Replacing characters or substrings: replace()
String Pool:

Java maintains a string pool to optimize memory usage.
When you create a string literal, it checks if an identical string already exists in the pool. If so, it returns the existing string instead of creating a new one.
Remember:

Choose strings for representing text data and performing text-related operations.
Be mindful of their immutability when working with strings.
Utilize the rich set of methods provided by the String class for various string manipulations.
I'm ready to provide more details or examples if you have specific questions!

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