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Dictionaries
Using .keys and .values

What if we don’t need to loop through both the keys and the values of a dictionary? We can use the properties .keys and .values to create collections of the keys and values of a dictionary that we can then loop through.

The .keys property stores a collection of dictionary keys, while the .values property stores a collection of dictionary values.

For example:

var fruitStand = [ "Apples": 12, "Bananas": 20, "Oranges": 18 ] print(fruitStand.keys)

The print() statement in the above snippet will output the following keys:

["Bananas", "Oranges", "Apples"]

If we printed fruitStand.values, our output would include these values:

[20, 18, 12]

We can use these properties to specify how we want to iterate through a dictionary.

For example, if we only need the names of the fruits to create a list of what we sell, we can iterate through just the keys of fruitStand by appending .keys to the dictionary:

for fruit in fruitStand.keys { print(fruit) }

This would give us an output similar to this:

"Oranges" "Apples" "Bananas"

We could append .values to fruitStand to loop through the values of our dictionary and find out the total number of fruit we have in stock:

var total = 0 for fruitStock in fruitStand.values { total += fruitStock } print(total) // Prints: 50

Instructions

1.

Underneath the declaration of total, create a for-in loop that iterates only through the values of the dictionary lemonadeStand.

Name the placeholder monthlyProfit and leave the body of the for-in loop empty for now.

2.

In the body of the loop, increase the value of total by the value of monthlyProfit.

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