Loops

Question 1

What is a for-in loop used for?

Answer 1

A for-in loop is used when the number of iterations is known before execution. It repeats a block of code for a set range or collection.
Example in Swift:
for i in 1…6 {
print(i)
} // Rolls a dice six times

Question 2

How does the random(in:) method work in Swift?

Answer 2

The random(in:) method generates a random number between a specified range.
Example in Swift:
let diceRoll = Int.random(in: 1…6) // Generates a random number between 1 and 6

Question 3

What is a while loop used for?

Answer 3

A while loop is used when the number of iterations is not known, and it continues executing as long as a condition is true.
Example in Swift:
while firstDice != secondDice {
firstDice = Int.random(in: 1…6)
secondDice = Int.random(in: 1…6)
} // Rolls dice until both are equal

Question 4

How is a repeat-while loop different from a while loop?

Answer 4

A repeat-while loop executes the block of code at least once before checking the condition, making sure the code runs before evaluating the condition.
Example in Swift:
repeat {
firstDice = Int.random(in: 1…6)
secondDice = Int.random(in: 1…6)
} while firstDice != secondDice // Rolls dice until both are equal, but always rolls at least once

Question 5

When should you use a repeat-while loop?

Answer 5

Use a repeat-while loop when you want to execute the loop at least once before checking the condition.
Example in Swift:
repeat {
print(“Running loop at least once”)
} while false // Executes once despite the false condition

Question 6

What is a Boolean type in Swift?

Answer 6

A Boolean type returns a value of either true or false.
Example in Swift:
let isLoggedIn = true

Question 7

What does the ‘equal to’ (==) operator do?

Answer 7

The ‘equal to’ operator checks if two values are equal, returning true if they are equal and false if they are not.
Example in Swift:
let isEqual = (5 == 5) // true

Question 8

What does the ‘greater than’ (>) operator do?

Answer 8

The ‘greater than’ operator checks if the value on the left is greater than the value on the right.
Example in Swift:
let isGreater = (10 > 5) // true

Question 9

What does the ‘less than’ (<) operator do?

Answer 9

The ‘less than’ operator checks if the value on the left is less than the value on the right.
Example in Swift:
let isLess = (3 < 5) // true

Question 10

What does the ‘greater than or equal to’ (>=) operator do?

Answer 10

The ‘greater than or equal to’ operator checks if the value on the left is greater than or equal to the value on the right.
Example in Swift:
let isGreaterOrEqual = (5 >= 5) // true

Question 11

What does the ‘less than or equal to’ (<=) operator do?

Answer 11

The ‘less than or equal to’ operator checks if the value on the left is less than or equal to the value on the right.
Example in Swift:
let isLessOrEqual = (5 <= 10) // true

Question 12

What does the ‘not equal to’ (!=) operator do?

Answer 12

The ‘not equal to’ operator checks if two values are not equal, returning true if they are not.
Example in Swift:
let isNotEqual = (5 != 3) // true

Question 13

What is the logical AND (&&) operator?

Answer 13

The logical AND operator returns true if both conditions are true.
Example in Swift:
let result = (5 > 3 && 10 > 7) // true

Question 14

What is the logical OR (||) operator?

Answer 14

The logical OR operator returns true if at least one condition is true.
Example in Swift:
let result = (5 > 3 || 3 > 10) // true

Question 15

What is the NOT (!) operator?

Answer 15

The NOT operator inverts the Boolean value, returning true if it was false, and false if it was true.
Example in Swift:
let isFalse = !(5 == 5) // false

Question 16

What is the Exclusive OR (XOR) operator?

Answer 16

The Exclusive OR (XOR) operator returns true if exactly one of the conditions is true, but false if both are true or both are false.
Example in Swift:
let result = (true ^ false) // true

Question 17

What is encryption?

Answer 17

Encryption is the process of converting information into scrambled code to protect it from unauthorized access.
Example:
When paying online, encryption secures your payment details.

Question 18

What is an if statement in Swift?

Answer 18

An if statement checks a condition and executes a block of code if the condition is true.
Example in Swift:
let isRaining = true
if isRaining {
print(“Bring an umbrella!”)
}

Question 19

What is an else statement in Swift?

Answer 19

An else statement runs a block of code if the condition in the if statement is false.
Example in Swift:
let isRaining = false
if isRaining {
print(“Bring an umbrella!”)
} else {
print(“No need for an umbrella!”)
}

Question 20

What is an else-if statement in Swift?

Answer 20

An else-if statement is used to check additional conditions after the initial if condition.
Example in Swift:
let position = 2
if position == 1 {
print(“You came first!”)
} else if position == 2 {
print(“You came second!”)
} else {
print(“You did not finish in the top two.”)
}

Question 21

How are Booleans used in conditional statements?

Answer 21

Booleans evaluate to either true or false and are used to determine if a condition is met.
Example in Swift:
let coldOutside = true
if coldOutside {
print(“Put on a warm coat.”)
}

Question 22

How does the logical AND (&&) operator work in Swift?

Answer 22

The AND (&&) operator returns true if both sides of the condition are true.
Example in Swift:
let temp = 70
if temp >= 68 && temp <= 72 {
print(“The temperature is just right!”)
} else {
print(“The temperature is too hot or too cold.”)
}

Question 23

How does the logical OR (||) operator work in Swift?

Answer 23

The OR (||) operator returns true if at least one side of the condition is true.
Example in Swift:
let mainsPower = false
let batteryPower = true
if mainsPower || batteryPower {
print(“I can use my phone!”)
} else {
print(“Better find a charger.”)
}