Ultimate Java Quick Reference - CodeWithHarry
1. // [comment]
Single line comment.
2. /* [comment] */
Multi line comment.
3. public
This can be imported
publically.
4. import [object].*
Imports everything in
object.
5. static
Going to be shared by every
[object].
6. final
Cannot be changed;
common to be defined with
all uppercase.
7. double
Integer with numbers that
can have decimals.
8. ;
Put after every command.
9. String
Just a string of characters.
10. Private
Can only be changed by a
method.
11. int
Can store numbers from 2^-
31 to 2^31.
12. fields are attributes
13. boolean
Can have true or false as
the value.
14. { }
These are used to start and
end a function, class, etc.
15. byte
These can store from -127 -
128.
16. long
Can store numbers from
2^127 to 2^-127.
17. char
Just lets you put in one
chracter.
18. double
64-bit number with
decimals.
19. float
32-bit number with
decimals.
20. protected
Can only be accessed by
other code in the package.
21. Scanner
This lets you get user input.
22. new [object
constructor]
This will let you create a
new object.
23. System.in
This lets you get data from
the keyboard.
24. public [class]()
This will be the constructor,
you use it to create new
objects.
25. super()
This will create the
superclass (the class it's
inheriting).
