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.

two. 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 a 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.
• Integer literals can be assigned to long.

6. Underscores in Literals (JDK 7):

• Makes reading large values ​​easier (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 new line, \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 quote
• \": Double quotes
• \: Backslash
• \r: Return by car
• \n: New line
• \f: Page feed
• \t: Horizontal tab
• \b: Backspace
• \ddd: Octal constant
• \uxxxx: Hexadecimal constant