Literals

Literals

1. What Is a Literal? (beginner)

A literal = value you type directly in code (not in a variable yet). 87, 3.14, 'A', "hi", true are all literals. Each has a type the compiler assumes.

2. Types with Examples (exam list)

Literal kind	Examples	Notes
Integer	10, 010 (octal!), 0xA (hex), 0b101 (binary), 1_000	default int; L → long
Floating	3.14 (double), 3.14f (float), 1e3 (=1000.0)	default double
Character	'A', `'
'(newline),'\u0041'` (=A)	single quotes only
String	"hi", `"a
b"`	double quotes, + joins
Boolean	true, false	no 0/1 in Java!
Null	null	no object (references only)

3. Code — Literals That Surprise Beginners

public class Lit {
    public static void main(String[] args) {
        System.out.println(010);    // 8! (leading 0 = octal)
        System.out.println(0xA);    // 10 (hex)
        System.out.println(1_000_000); // 1000000 (_ for readability)
        System.out.println('A' + 1);   // 66 (char + int = int!)
        System.out.println("5" + 5);   // "55" (String + int = String!)
        // int x = null; // ERROR — null only for objects
        String s = null; // ok
    }
}

4. Traps

• "A" (String) ≠ 'A' (char) — quotes matter.
• 010 is octal (8), not ten! Never pad integers with 0.
• 3.14 is double: float f = 3.14; fails, need 3.14f.

5. Exam Points

• Literal types + suffixes (L, f, _) — 5 marks, frequent.
• Octal/hex/binary + escape ( , \u) — 3 marks, frequent.
• Predict output ("5"+5, 'A'+1) — 2-3 mark favourite.