Chapter II

Question 1

Primitive type

Answer 1

boolean 
byte
short
int
long
float
double
char

Question 2

boolean

Answer 2

true or false

Question 3

byte

Answer 3

8-bit integral value - 123 → Stores whole numbers from -128 to 127

Question 4

short

Answer 4

16-bit integral value - 123 → Stores whole numbers from -32,768 to 32,767

Question 5

int

Answer 5

32-bit integral value - 123 →Stores whole numbers from -2,147,483,648 to 2,147,483,647

Question 6

long

Answer 6

64-bit integral value -123L → Stores whole numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

Question 7

float

Answer 7

32-bit floating-point value - 123.45f →Stores fractional numbers. Sufficient for storing 6 to 7 decimal digits

Question 8

double

Answer 8

64-bit floating-point value - 123.456 →Stores fractional numbers. Sufficient for storing 15 decimal digits

Question 9

char

Answer 9

16-bit Unicode value - ‘a’

Question 10

Conventions

Answer 10

Method and variable names are written in camelCase with the first letter being lowercase
Class and interface names are written in camelCase with the first letter being uppercase. Also, don’t start any class name with $, as the compiler uses this symbol for some files

Question 11

var

Answer 11

A var is used as a local variable in a constructor, method, or initializer block.
A var cannot be used in constructor parameters, method parameters, instance variables, or class variables.
A var is always initialized on the same line (or statement) where it is declared.
The value of a var can change, but the type cannot.
A var cannot be initialized with a null value without a type.
A var is not permitted in a multiple variable declaration.
A var is a reserved type name but not a reserved word, meaning it can be used as an identifier except as a class, interface, or enum name.

Question 12

Local variables scope

Answer 12

In scope from declaration to end of block

Question 13

Instance variables

Answer 13

In scope from declaration until object eligible for garbage collection. (field of objects)

Question 14

Class variables

Answer 14

In scope from declaration until program ends. (static variables)

Question 15

Object is not longer reachable when

Answer 15

The object no longer has any references pointing to it.

All references to the object have gone out of scope.

Question 16

finalize() how many time can run

Answer 16

Can run zero or one times. It cannot run twice