Iterating through a dictionary

If we wanted to loop through every key and value in a dictionary using a for-in loop, the syntax would look as follows:

for (keyHolder, valueHolder) in dictionaryName {
  // Body of loop
}

// Since dictionaries have both keys and values, we group them together in parentheses () and separate them by a comma.

Having two or more values wrapped in parentheses () and separated by commas , is called a tuple.

EXAMPLE:

Let’s create a dictionary that stores the names and grades of individual students in a class. If we want to view each student’s name and their grade:

var classGrades = [
  "Raymond": 100,
  "Rosa": 82,
  "Jake": 73,
  "Terry": 90
]

for (name, grade) in classGrades {
  print("\(name) has a grade of \(grade)")
}

OUTPUT:
Rosa has a grade of 82
Raymond has a grade of 100
Jake has a grade of 73
Terry has a grade of 90

EXAMPLE:

var mythology = [
  "Zeus": "Jupiter",
  "Athena": "Minerva", 
  "Poseidon": "Neptune",
  "Demeter": "Ceres"]

// Write your code below 🏛️ 
for (greekName, romanName) in mythology {
  print ("\(greekName) is also known as \(romanName)")
}

OUTPUT:
Poseidon is also known as Neptune
Demeter is also known as Ceres
Athena is also known as Minerva
Zeus is also known as Jupiter