How to Convert an Array of Key-Value Pairs to a Dictionary in Swift

How to Convert an Array of Key-Value Pairs to a Dictionary in Swift ?

Answer

To convert an array of key-value pairs to a dictionary in Swift, you can use the `Dictionary(uniqueKeysWithValues:)` initializer. This allows you to create a dictionary from a collection of key-value pairs stored in an array.


✐ Examples

1 Converting an Array of Tuples to a Dictionary

We can convert an array of key-value pairs to a dictionary in Swift using the `Dictionary(uniqueKeysWithValues:)` initializer. This example demonstrates how to declare and initialize an array of key-value pairs, use the `Dictionary(uniqueKeysWithValues:)` initializer to convert the array to a dictionary, and print the resulting dictionary.

For example,

  1. We start by declaring and initializing an array of key-value pairs named pairs. In this example, the pairs are represented as tuples with two elements: a key and a value.
  2. We use the `Dictionary(uniqueKeysWithValues:)` initializer to convert the array to a dictionary.
  3. We print the resulting dictionary.

Swift Program

let pairs = [(1, 10), (2, 20), (3, 30)]

// Convert the array to a dictionary using Dictionary(uniqueKeysWithValues:)
let myDictionary = Dictionary(uniqueKeysWithValues: pairs)

// Print the resulting dictionary
print("Dictionary from array of tuples:")
for (key, value) in myDictionary {
    print("Key: \(key), Value: \(value)")
}

Output

Dictionary from array of tuples:
Key: 1, Value: 10
Key: 2, Value: 20
Key: 3, Value: 30

2 Converting an Array of KeyValuePairs to a Dictionary

We can convert an array of `KeyValuePair` to a dictionary in Swift using the `Dictionary(uniqueKeysWithValues:)` initializer. This example demonstrates how to declare and initialize an array of `KeyValuePair`, use the `Dictionary(uniqueKeysWithValues:)` initializer to convert the array to a dictionary, and print the resulting dictionary.

For example,

  1. We start by declaring and initializing an array of `KeyValuePair` named pairs.
  2. We use the `Dictionary(uniqueKeysWithValues:)` initializer to convert the array to a dictionary.
  3. We print the resulting dictionary.

Swift Program

let pairs: [KeyValuePairs<Int, Int>.Element] = [(1, 10), (2, 20), (3, 30)]

// Convert the array to a dictionary using Dictionary(uniqueKeysWithValues:)
let myDictionary = Dictionary(uniqueKeysWithValues: pairs)

// Print the resulting dictionary
print("Dictionary from array of KeyValuePair:")
for (key, value) in myDictionary {
    print("Key: \(key), Value: \(value)")
}

Output

Dictionary from array of KeyValuePair:
Key: 1, Value: 10
Key: 2, Value: 20
Key: 3, Value: 30

3 Converting an Array of Arrays to a Dictionary

We can convert an array of arrays to a dictionary in Swift using the `Dictionary(uniqueKeysWithValues:)` initializer. This example demonstrates how to declare and initialize an array of arrays, use the `Dictionary(uniqueKeysWithValues:)` initializer to convert the array to a dictionary, and print the resulting dictionary.

For example,

  1. We start by declaring and initializing an array of arrays named pairs. In this example, the arrays contain two elements: a key and a value.
  2. We use the `Dictionary(uniqueKeysWithValues:)` initializer to convert the array to a dictionary.
  3. We print the resulting dictionary.

Swift Program

let pairs = [[1, 10], [2, 20], [3, 30]]

// Convert the array to a dictionary using Dictionary(uniqueKeysWithValues:)
let myDictionary = Dictionary(uniqueKeysWithValues: pairs.map { ($0[0], $0[1]) })

// Print the resulting dictionary
print("Dictionary from array of arrays:")
for (key, value) in myDictionary {
    print("Key: \(key), Value: \(value)")
}

Output

Dictionary from array of arrays:
Key: 1, Value: 10
Key: 2, Value: 20
Key: 3, Value: 30

Summary

In this tutorial, we learned How to Convert an Array of Key-Value Pairs to a Dictionary in Swift language with well detailed examples.


More Swift Dictionaries Tutorials

  1. How to create an Empty Dictionary in Swift ?
  2. How to create a Dictionary with Initial Key-Value Pairs in Swift ?
  3. How to Print a Dictionary in Swift ?
  4. How to Add a Key-Value Pair to a Dictionary in Swift ?
  5. How to Set a Default Value for a Key in a Dictionary in Swift ?
  6. How to Update the Value for a Key in a Dictionary in Swift ?
  7. How to Check if a Dictionary is Empty in Swift ?
  8. How to Check if a Key Exists in a Dictionary in Swift ?
  9. How to Check if a Value Exists in a Dictionary in Swift ?
  10. How to Get the Value Associated with a Key in a Dictionary in Swift ?
  11. How to Remove a Key-Value Pair from a Dictionary in Swift ?
  12. How to Remove Key-Value Pairs from a Dictionary Based on Values in Swift ?
  13. How to Clear all Key-Value Pairs from a Dictionary in Swift ?
  14. How to Iterate over Keys in a Dictionary in Swift ?
  15. How to Iterate over Values in a Dictionary in Swift ?
  16. How to Iterate over Entries (Key-Value Pairs) in a Dictionary in Swift ?
  17. How to Get the Size (Number of Key-Value Pairs) of a Dictionary in Swift ?
  18. How to Convert a Dictionary to an Array of Keys in Swift ?
  19. How to Convert a Dictionary to an Array of Values in Swift ?
  20. How to Convert a Dictionary to an Array of Key-Value Pairs in Swift ?
  21. How to Merge Two Dictionaries in Swift ?
  22. How to Clone a Dictionary in Swift ?
  23. How to Check if Two Dictionaries are Equal in Swift ?
  24. How to Sort a Dictionary by Keys in Swift ?
  25. How to Sort a Dictionary by Values in Swift ?
  26. How to Filter a Dictionary Based on Keys in Swift ?
  27. How to Filter a Dictionary Based on Values in Swift ?
  28. How to Reduce Values in a Dictionary to a Single Value in Swift ?
  29. How to Convert an Array of Key-Value Pairs to a Dictionary in Swift ?
  30. How to Convert a Dictionary to a JSON String in Swift ?
  31. How to Convert a JSON String to a Dictionary in Swift ?
  32. How to Swap Keys and Values in a Dictionary in Swift ?
  33. How to Create a Dictionary of Dictionaries in Swift ?
  34. How to Iterate Over a Dictionary of Dictionaries in Swift ?