Methods

Question 1

Define method

Answer 1

a named block of parameterized code associated with one or more objects

Question 2

Define method invocation

Answer 2

specifies the method name, the object on which it is to be invoked (sometimes called the receiver), and zero or more argument values that are assigned to the named method parameters.

Question 3

What is the value of a method invocation expression?

Answer 3

the last expression evaluated in the method

Question 4

Methods are objects. T/F?

Answer 4

False

Question 5

It is possible to create an object from a method. T/F?

Answer 5

True

Question 6

How are methods different from blocks?

Answer 6

They are named and do not have to be invoked with an iterator method.

Question 7

What is it called when an object represents a block?

Answer 7

a proc

Question 8

What are the two kinds of proc objects?

Answer 8

lamdas and procs

Question 9

What do we mean when we say a proc object is a closure?

Answer 9

retain access to the local variables that were in scope when they were defined, even when the proc or lambda is invoked from a different scope.

Question 10

What keyword is used to define a keyword?

Answer 10

def

Question 11

What value is returned from a method if no expression follows the return keyword?

Answer 11

nil

Question 12

When must an explicit return value be used?

Answer 12

When more than one value needs to be returned.

Question 13

What is a singleton method?

Answer 13

A method defined for just a single object.

Question 14

What keyword is used to undefine a method?

Answer 14

undef

Question 15

undefine can be used to undefine a method is a subclass but not the parent class. T/F?

Answer 15

true

Question 16

What method can be used to undefine a method?

Answer 16

undef_method

Question 17

What punctuation marks can method names end with?

Answer 17

question mark, equal sign, or exclamation point

Question 18

What does an equal sign at the end of a method name indicate?

Answer 18

that it’s a setter method

Question 19

What does a question mark at the end of a method name often signify?

Answer 19

That it returns a boolean value.

Question 20

What does the Numeric method nonzero? return?

Answer 20

nil if it is zero or the number if it is not zero

Question 21

What does an exclamation point at the end of a method name usually signify?

Answer 21

That the object passed to the method will be modified by the method.

Question 22

Mutating methods that do not have a nonmutating variant do not typically have an exclamation point. T/F?

Answer 22

true

Question 23

What does the exit! method do?

Answer 23

aborts the program immediately without running any END blocks or shutdown hooks registered with at_exit.exit!

Question 24

exit! is not a mutator. T/F?

Answer 24

True