Topic 1.1: Java Basics - Define the scope of variables

Question 1

By default in java the variable with the closest scope takes precedence and hides access to the variable with the same name but in a longer scope.

Answer 1

how is
shadowing
in variables resolved by java

Question 2

what is the place of declaration and the place of initialisation of
local variables

Answer 2

Place of declaration: Can be defined in a constructor, method, or code block.
Place of initialization: Local variables should be initialized at the point of declaration. (they will not be given default values if not explicitly initialised)

Question 3

Place of declaration: Can be defined in a constructor, method, or code block.
Place of initialization: Local variables should be initialized at the point of declaration. (they will not be given default values if not explicitly initialised)

Answer 3

what is the place of declaration and the place of initialisation of
local variables

Question 4

what is the place of declaration and the place of initialisation of
Instance Variables (Fields)

Answer 4

Place of declaration: Defined within the class but outside constructors and methods.
Place of initialization: Typically initialized within the constructor.

Question 5

what 2 ways can
shadowing
in variables be resolved by the programmer

Answer 5

to resolve this the programmer may:
* change the name of the variables with a shared name
* use the this keyword to explicitly access the instance variables

Question 6

name 3 situations of
Shadowing
in Variables

Answer 6

Three situations of this occuring are:
* A parameter shadows a field.
* A local variable shadows a field.
* A local variable shadows a parameter.

Question 7

Scope: Throughout the class, accessible from any constructor, method, or code block.
Lifetime: As long as the program is running.

Answer 7

what is the scope and lifetime of
Class Variables (Static Variables)

Question 8

Place of declaration: Defined within the class but outside constructors and methods.
Place of initialization: Can be initialized at declaration or using a static block.

Answer 8

what is the place of declaration and the place of initialisation of
Class Variables (Static Variables)

Question 9

Place of declaration: Defined within the class but outside constructors and methods.
Place of initialization: Typically initialized within the constructor.

Answer 9

what is the place of declaration and the place of initialisation of
Instance Variables (Fields)

Question 10

how is
shadowing
in variables resolved by java

Answer 10

By default in java the variable with the closest scope takes precedence and hides access to the variable with the same name but in a longer scope.

Question 11

to resolve this the programmer may:
* change the name of the variables with a shared name
* use the this keyword to explicitly access the instance variables

Answer 11

what 2 ways can
shadowing
in variables be resolved by the programmer

Question 12

what is the place of declaration and the place of initialisation of
Class Variables (Static Variables)

Answer 12

Place of declaration: Defined within the class but outside constructors and methods.
Place of initialization: Can be initialized at declaration or using a static block.

Question 13

define
Shadowing
in Variables

Answer 13

This occurs when two separate variables share the same name and are both in scope

Question 14

Place of declaration: Declared within the header of the constructor or method.

Place of initialization: Initialized when the constructor or method is invoked.

Answer 14

what is the place of declaration and the place of initialisation of
Constructor and Method Parameters (Formal Parameters)

Question 15

what is the scope and lifetime of
Constructor and Method Parameters (Formal Parameters)

Answer 15

Scope: Limited to the constructor or method block they are declared in.

Lifetime: Exist as long as the constructor or method is executing.

Question 16

Scope: Throughout the class, accessible from any constructor, method, or code block.

Lifetime: As long as the instance exists.

Answer 16

what is the scope and lifetime of
Instance Variables (Fields)

Question 17

Three situations of this occuring are:
* A parameter shadows a field.
* A local variable shadows a field.
* A local variable shadows a parameter.

Answer 17

name 3 situations of
Shadowing
in Variables

Question 18

Scope: Limited to the code block they are declared in.
Lifetime: From declaration to the end of the code block.

Answer 18

what is the scope and lifetime of
local variables

Question 19

what is the scope and lifetime of
local variables

Answer 19

Scope: Limited to the code block they are declared in.
Lifetime: From declaration to the end of the code block.

Question 20

This occurs when two separate variables share the same name and are both in scope

Answer 20

define
Shadowing
in Variables

Question 21

Scope: Limited to the constructor or method block they are declared in.

Lifetime: Exist as long as the constructor or method is executing.

Answer 21

what is the scope and lifetime of
Constructor and Method Parameters (Formal Parameters)

Question 22

what is the scope and lifetime of
Instance Variables (Fields)

Answer 22

Scope: Throughout the class, accessible from any constructor, method, or code block.

Lifetime: As long as the instance exists.

Question 23

what is the place of declaration and the place of initialisation of
Constructor and Method Parameters (Formal Parameters)

Answer 23

Place of declaration: Declared within the header of the constructor or method.

Place of initialization: Initialized when the constructor or method is invoked.

Question 24

what is the scope and lifetime of
Class Variables (Static Variables)

Answer 24

Scope: Throughout the class, accessible from any constructor, method, or code block.
Lifetime: As long as the program is running.