Swift basics

Question 1

How to declare a variable?

Answer 1

var hello = “Hello”

Question 2

How to declare a constant?

Answer 2

let hello = hello

Question 3

How to print in the console?

Answer 3

println()

Question 4

How to add a new line and a tab in a string?

Answer 4

• New line: \n
• Tab: \t

Question 5

How to add an emoji to a string

Answer 5

1. Go to edit
2. Special characters

Question 6

How to convert an int to double?

Answer 6

Double(number)

Question 7

How to add an element to an array?

Answer 7

• array.append()
• array +=

Question 8

How to get the size of an array?

Answer 8

array.count

Question 9

how to declare a for loop?

Answer 9

1)

for item in array {

}

2)

for item in 1…10 {

}

3)

for var i = 0; i < todo.count; i++ {

}

Question 10

How to declare a while loop?

Answer 10

var index = 0

while index < todo.count {

println(“hello”)

index++

}

Question 11

How to declare a function?

Answer 11

func calculate(height: int, width: int) -> Int{

return

}

Question 12

What is an optional?

Answer 12

• Returns nil or a some object
• To make a function an optional put ? after the Type
• if let ss = function() {}

Question 13

Characteristics of an enum

Answer 13

• emum is a type
• It is used for representing days of the week, etc
• The name and the elements of the enum must begin with Capital Letter.
• You can put methods inside an Enum
• enum Days { case Monday, Tuesday}
• enum Days: Int { case Monday = 1, Tuesday = 2}
• Days.Monday.rawValue to obtain the raw value

Question 14

What is a struct?

Answer 14

• It is a command used to create a data type like Car or Contact

struct Car() {

var speed: Int

var color = “red”

}

var lambo = Car(parameters)

• create an init() to modify the custom initiali