Chapter 01 Cheatsheet

Main method parameter

1. String[] args
2. String options[]
3. String... friends

Ordering elements in class

1. Package
2. Import
3. Top-level type declaration
4. Field declaration
5. Method declaration

Primitives

1. boolean: false
2. byte: 0
3. short: 0
4. int: 0
5. long: 0L
6. float: 0.0f (without lowercase l or uppercase L, it will be treated as int)
7. double: 0.0 (without lowercase f or uppercase f, it will be treated as double)
8. char: \u0000

Garbage collection

• When there is no reference to an object in a currently live thread
• When there are no references pointing to the object
• When all references to the object gone out of scope

❌ Invalid underscore position

1. not at the start -> _1000.00
2. not at the end -> 10000.00_
3. not beside decimal -> 100_.00