Codecademy Logo

Conditionals

Print Cheatsheet

if Statement

An if statement executes a code block when its condition evaluates to true. If the condition is false, the code block does not execute.

var halloween = true
if halloween {
print("Trick or treat!")
}
// Prints: Trick or treat!

else Statement

An else statement is a partner to an if statement. When the condition for the if statement evaluates to false, the code within the body of the else will execute.

var turbulence = false
if turbulence {
print("Please stay seated.")
} else {
print("You may freely move around.")
}
// Prints: You may freely move around.

else if Statement

An else if statement provides additional conditions to check for within a standard if/else statement. else if statements can be chained and exist only after an if statement and before an else.

var weather = "rainy"
if weather == "sunny" {
print("Grab some sunscreen")
} else if weather == "rainy" {
print("Grab an umbrella")
} else if weather == "snowing" {
print("Wear your snow boots")
} else {
print("Invalid weather")
}
// Prints: Grab an umbrella

Comparison Operators

Comparison operators compare the values of two operands and return a Boolean result:

  • < less than
  • > greater than
  • <= less than or equal to
  • >= greater than or equal to
  • == equal to
  • != not equal to
5 > 1 // true
6 < 10 // true
2 >= 3 // false
3 <= 5 // true
"A" == "a" // false
"B" != "b" // true

Ternary Conditional Operator

The ternary conditional operator, denoted by a ?, creates a shorter alternative to a standard if/else statement. It evaluates a single condition and if true, executes the code before the :. If the condition is false, the code following the : is executed.

var driverLicense = true
driverLicense ? print("Driver's Seat") : print("Passenger's Seat")
// Prints: Driver's Seat

switch Statement

The switch statement is a type of conditional used to check the value of an expression against multiple cases. A case executes when it matches the value of the expression. When there are no matches between the case statements and the expression, the default statement executes.

var secondaryColor = "green"
switch secondaryColor {
case "orange":
print("Mix of red and yellow")
case "green":
print("Mix of blue and yellow")
case "purple":
print("Mix of red and blue")
default:
print("This might not be a secondary color.")
}
// Prints: Mix of blue and yellow

switch Statement: Interval Matching

Intervals within a switch statement’s case provide a range of values that are checked against an expression.

let year = 1905
var artPeriod: String
switch year {
case 1860...1885:
artPeriod = "Impressionism"
case 1886...1910:
artPeriod = "Post Impressionism"
case 1912...1935:
artPeriod = "Expressionism"
default:
artPeriod = "Unknown"
}
// Prints: Post Impressionism

switch Statement: Compound Cases

A compound case within a switch statement is a single case that contains multiple values. These values are all checked against the switch statement’s expression and are separated by commas.

let service = "Seamless"
switch service {
case "Uber", "Lyft":
print("Travel")
case "DoorDash", "Seamless", "GrubHub":
print("Restaurant delivery")
case "Instacart", "FreshDirect":
print("Grocery delivery")
default:
print("Unknown service")
}
// Prints: Restaurant delivery

switch Statement: where Clause

Within a switch statement, a where clause is used to test additional conditions against an expression.

let num = 7
switch num {
case let x where x % 2 == 0:
print("\(num) is even")
case let x where x % 2 == 1:
print("\(num) is odd")
default:
print("\(num) is invalid")
}
// Prints: 7 is odd