What is CharSequence?

CharSequence is an interface in Java that represents a sequence of characters accessible for reading.

Key features:

• Immutability: It represents an immutable sequence of characters.
• Index access: Allows access to characters by their index.
• Subtypes: Implemented by classes such as String, StringBuilder, StringBuffer.

Main methods:

Method	Description
length()	Returns the length of the character sequence.
charAt(int index)	Returns the character at the specified index.
subSequence(int start, int end)	Returns a subsequence.
toString()	Returns a string representation.

String represents an immutable sequence of characters, while StringBuilder and StringBuffer provide mutable sequences. CharSequence serves as a common type for working with all these implementations.

Example usage:

// Often used in Android in methods that accept text
void setText(CharSequence text) {
    // work with the character sequence
}