Getting Started with App Development [Section 3: Constants, Variables, & Data Types]

Question 1

___________ are most frequently used to explain difficult sections of code, provide copyright information, at the top of a file, and to offer dating information

Answer 1

Comments

Question 2

Swift also supports ___________ _____________, which group multiple values into a single constant or variable

Answer 2

collection types

Question 3

One collection type is named an __________; it stores an ordered list of values

Answer 3

Array

Question 4

Another collection type is named a __________, which contains keys that help you look up specific values

Answer 4

Dictionary

Question 5

Here’s an example of creating a type definition

Answer 5

struct Person {
let firstName: String
let lastName: String

func sayHello() {
print(”Hello there! My name is (firstName) (lastName).”)
}
}

Question 6

A ________ _________ declares the information it stores and its capabilities or actions

Answer 6

type definition

Question 7

The information that a type definition stores

Answer 7

property

Question 8

A type definition’s action/ capability

Answer 8

method

Question 9

When creating a type and assigning it to a variable or constant, you’re making a version or ________ of the type

Answer 9

instance

Question 10

Swift is a type-_______ language

Answer 10

safe

Question 11

Type-safe languages encourage or require clarity about the types of values your ______ can work with

Answer 11

code

Question 12

When compiling your code, Swift performs _________ __________ on all of your constraints and variables; it also flags any mismatched types as errors

Answer 12

type checking

Question 13

In Swift, you’re unable to assign a ________ of one type to a variable of another type

Answer 13

variable

Question 14

Swift allows you to put _________ in your numbers as a way of formatting for easier reading

Answer 14

underscores

e.g.,

var largeUglyNumber = 1000000000
var largePrettyNumber = 1_000_000_000

Question 15

Swift uses _________ __________ to make assumptions about the type based on the value assigned to the constant or variable

Answer 15

type inference

e.g.,

let cityName = “San Francisco”
// “San Francisco” is obviously a String, so the compiler
automatically assigns the type of cityName to a String.

let pi = 3.1415927
// 3.1415927 is a number with decimal points, so the compiler
automatically assigns the type pi to a Double.

Question 16

A case when it’s useful/ required to explicitly specify the type of a constant or variable is known as a…

Answer 16

type annotation

e.g.,

let cityName: String = “San Francisco”

let pi: Double = 3.1415927

Question 17

Whenever you define a constant or variable, you must either specify a type using a type annotation or _________ it a value that the compiler can use to infer the type

Answer 17

assign