How to Create a Dictionary of Dictionaries in Swift - Step by Step Examples

How to Create a Dictionary of Dictionaries in Swift ?

Answer

To create a dictionary of dictionaries in Swift, you can declare a dictionary where the value type is another dictionary. This allows you to create nested dictionaries, with each key in the outer dictionary mapping to another dictionary.

✐ Examples

1 Creating a Dictionary of Dictionaries

We can create a dictionary of dictionaries in Swift by declaring a dictionary where the value type is another dictionary. This example demonstrates how to declare and initialize a dictionary of dictionaries, add key-value pairs to the inner dictionaries, and print the resulting nested dictionary.

For example,

We start by declaring and initializing a dictionary named outerDict where the value type is another dictionary.
We add key-value pairs to the inner dictionaries.
We print the resulting nested dictionary.

Swift Program

var outerDict: [String: [String: Int]] = [
    "A": ["X": 1, "Y": 2],
    "B": ["Z": 3]
]

// Print the resulting nested dictionary
print("Dictionary of dictionaries:")
for (outerKey, innerDict) in outerDict {
    print("Key: \(outerKey)")
    for (innerKey, value) in innerDict {
        print("  Inner Key: \(innerKey), Value: \(value)")
    }
}

Output

Dictionary of dictionaries:
Key: A
  Inner Key: X, Value: 1
  Inner Key: Y, Value: 2
Key: B
  Inner Key: Z, Value: 3

2 Creating and Adding to a Dictionary of Dictionaries Dynamically

We can create and add to a dictionary of dictionaries dynamically in Swift by declaring a dictionary where the value type is another dictionary. This example demonstrates how to declare the outer dictionary, add inner dictionaries dynamically, add key-value pairs to the inner dictionaries, and print the resulting nested dictionary.

For example,

We start by declaring the outer dictionary named outerDict where the value type is another dictionary.
We add inner dictionaries dynamically.
We add key-value pairs to the inner dictionaries.
We print the resulting nested dictionary.

Swift Program

var outerDict: [String: [String: Int]] = [:]

// Add inner dictionaries dynamically
outerDict["A"] = [:]
outerDict["B"] = [:]

// Add key-value pairs to the inner dictionaries
outerDict["A"]?["X"] = 1
outerDict["A"]?["Y"] = 2
outerDict["B"]?["Z"] = 3

// Print the resulting nested dictionary
print("Dictionary of dictionaries:")
for (outerKey, innerDict) in outerDict {
    print("Key: \(outerKey)")
    for (innerKey, value) in innerDict {
        print("  Inner Key: \(innerKey), Value: \(value)")
    }
}

Output

Dictionary of dictionaries:
Key: A
  Inner Key: X, Value: 1
  Inner Key: Y, Value: 2
Key: B
  Inner Key: Z, Value: 3

Summary

In this tutorial, we learned How to Create a Dictionary of Dictionaries in Swift language with well detailed examples.

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How to Create a Dictionary of Dictionaries in Swift - Step by Step Examples