How to create an Empty Dictionary in Swift

How to create an Empty Dictionary in Swift ?

Answer

To create an empty dictionary in Swift, you can use the `Dictionary` type with specific key and value types or shorthand syntax. A dictionary is a collection of key-value pairs where each key must be unique.


✐ Examples

1 Creating an Empty Dictionary with Integer Keys and String Values

We can create an empty dictionary in Swift where the keys are integers and the values are strings. This example demonstrates how to initialize an empty dictionary and add key-value pairs to it.

For example,

  1. We start by declaring and initializing an empty dictionary named myDictionary with integer keys and string values.
  2. We add some key-value pairs to the dictionary.
  3. We print the dictionary contents to verify the key-value pairs.

Swift Program

var myDictionary: [Int: String] = [:]

// Add key-value pairs to the dictionary
myDictionary[1] = "One"
myDictionary[2] = "Two"
myDictionary[3] = "Three"

// Print the dictionary contents
print("Dictionary contents:")
for (key, value) in myDictionary {
    print("Key: \(key), Value: \(value)")
}

Output

Dictionary contents:
Key: 1, Value: One
Key: 2, Value: Two
Key: 3, Value: Three

2 Creating an Empty Dictionary with String Keys and Double Values

We can create an empty dictionary in Swift where the keys are strings and the values are doubles. This example demonstrates how to initialize an empty dictionary and add key-value pairs to it.

For example,

  1. We start by declaring and initializing an empty dictionary named myDictionary with string keys and double values.
  2. We add some key-value pairs to the dictionary.
  3. We print the dictionary contents to verify the key-value pairs.

Swift Program

var myDictionary: [String: Double] = [:]

// Add key-value pairs to the dictionary
myDictionary["A"] = 1.1
myDictionary["B"] = 2.2
myDictionary["C"] = 3.3

// Print the dictionary contents
print("Dictionary contents:")
for (key, value) in myDictionary {
    print("Key: \(key), Value: \(value)")
}

Output

Dictionary contents:
Key: A, Value: 1.1
Key: B, Value: 2.2
Key: C, Value: 3.3

Summary

In this tutorial, we learned How to create an Empty 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 ?