Literals in Java

Literals in Java

1. Definition of Literals:

• Fixed values represented in human-readable form (e.g., number 100).
• Also called constants.
• Intuitive and frequently used.

2. Types of Literals:

• Primitive Types: Can be any primitive data type.
• Characters: Delimited by single quotes (e.g., 'a', '%').

3. Integer Literals:

• Numbers without fractional components (e.g., 10, -100).
• Represented as int by default.
• Can be specified as long using l or L (e.g., 12L).

4. Floating Point Literals:

• Include a decimal point and fractional component (e.g., 11,123).
• Represented as double by default.
• Can be specified as float using F or f (e.g., 10.19F).
• Support scientific notation.

5. Assignment to Variables:

• Integer literals can be assigned to char, byte, short if the value fits.
• Entire literals can be assigned to long.

6. Underscores in Literals (JDK 7+):

• Makes it easier to read large values (e.g., 123_45_1234).

7. Hexadecimal, Octal and Binary Literals:

• Hexadecimals: Start with 0x or 0X (e.g., 0xFF).
• Octals: Start with zero (e.g., 011).
• Binaries (JDK 7+): Start with 0b or 0B (e.g., 0b1100).

8. Character Escape Sequences:

• Used to represent special characters (e.g., n for newline, t for tab).
• Examples: ch = 't';, ch = ''';.

9. String Literals:

• Set of characters enclosed in double quotes (e.g., "this is a test").
• May contain escape sequences (e.g., n, t).

Example of use in System.out.println:

System.out.println("First line\nSecond line"); System.out.println("A\tB\tC");

10. Escape Sequence Table:

• ': Single quotes
• ": Double quotes
• : Backslash
• r: Return by car
• n: New line
• f: Page feed
• t: Horizontal tab
• b: Rewind
• ddd: Octal constant
• uxxxx: Hexadecimal constant

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