If and if-else statements in Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of an if statement in Swift?

An if statement lets your program make decisions by running code only when a condition is true.

beginner

How does an if-else statement work?

It runs one block of code if the condition is true, and a different block if the condition is false.

beginner

What will this Swift code print?<br><pre>let age = 18
if age >= 18 {
  print("Adult")
} else {
  print("Minor")
}</pre>

It will print Adult because the age is 18, which meets the condition age >= 18.

beginner

Can an if statement run without an else?

Yes. You can use if alone to run code only when a condition is true, and do nothing if it is false.

intermediate

What is the syntax to check multiple conditions in Swift?

You can use else if between if and else to check more than one condition.

What does this Swift code do?<br>

if temperature > 30 {
  print("Hot")
} else {
  print("Cool")
}

A Does nothing

B Always prints "Hot"

C Prints "Cool" if temperature is more than 30

D Prints "Hot" if temperature is more than 30, otherwise prints "Cool"

The if checks if temperature is greater than 30. If true, it prints "Hot"; otherwise, it prints "Cool".

Which keyword starts a condition check in Swift?

A when

B check

C if

D condition

The keyword if is used to start a condition check.

What happens if the if condition is false and there is no else?

A Nothing happens, the program skips the <code>if</code> block

B The code inside <code>if</code> runs anyway

C The program crashes

D The program asks for input

If the condition is false and there is no else, the program skips the if block and continues.

How do you check multiple conditions in Swift?

A Using multiple <code>if</code> statements only

B Using <code>else if</code> between <code>if</code> and <code>else</code>

C Using <code>switch</code> only

D Using <code>for</code> loops

You use else if to check multiple conditions in sequence.

What will this code print?<br>

let score = 75
if score >= 90 {
  print("A")
} else if score >= 80 {
  print("B")
} else {
  print("C")
}

A "C"

B "A"

C "B"

D Nothing

Since 75 is less than 80, it does not meet the first two conditions, so it prints "C".

Explain how an if-else statement helps a program make decisions.

Think about choosing between two paths based on a yes/no question.

Write a simple Swift if statement that prints "Good morning" if a variable hour is less than 12.

Use the <code>if</code> keyword and a comparison operator.