Intro to Ruby Book

Question 1

variables

Answer 1

used to store information to be referenced and manipulated in a computer program, provide a way of labeling data with a descriptive name

Question 2

like containers that hold info

Answer 2

variables

Question 3

.chomp

Answer 3

used after any string to remove the extra characters at the end

Question 4

method

Answer 4

(early defintion) pieces of reusable code that a program can execute many times

Question 5

How is a block delimited?

Answer 5

IT is delimited by either { }, or do/end

Question 6

Ruby methods ALWAYS return the evaluated result of the last line of the expression unless an explicit xxxx comes before it.

Answer 6

RETURN

Question 7

Method analogy

Answer 7

Like a hammer in your backback

Question 8

Does the pop method mutate the caller?

Answer 8

Yes, the original array variable is modified

Question 9

How do you add an item back to an array permanently?

Answer 9

array.push
OR («)

Question 10

The _____ method iterates over an array applying a block to each element of the array and returns a new array with those results.

Answer 10

map or collect method

Question 11

Is a map/collect method destructive? (Does it mutate the caller)

Answer 11

No it does not mutate the caller

Question 12

Object ID

Answer 12

Every Object has a unique object ID

x.object_id

Question 13

How do you get two of the same object ID?

Answer 13

if 2 immutable objects have the same value they have the same object ID

Question 14

The calling object

Answer 14

The object that the method is invoked upon

Question 15

What can be passed to methods as arguments

Answer 15

Only objects (not variables)

Question 16

Usually ____ have a “meaningful” return value that is meant to be “used” in some way

Answer 16

non-mutating methods

Question 17

Map vs. Each

Answer 17

If you want to change your return value: use map. If you want to use the same return value that you started with use .each. (Each is more flexible).

Question 18

What is the return value of .each?

Answer 18

The same value as the original array

Question 19

What will the input be?
def speak(words)
puts words
end

speak(“There are around 700 separate programming languages”)

Answer 19

You can pass in a string as an argument without putting it in a local valuable first.

output: There are around 700 separate programming languages

Question 20

year = 1986

def virus(year)
puts “The first computer virus was created in #{year}
end

virus

Answer 20

ERROR

Question 21

default paramaters

Answer 21

you can invoke the method without passing an argument

Question 22

Arguments are used in….

Answer 22

method invocations

Question 23

Parameters are used in…

Answer 23

method definitions