How to Iterate over Entries (Key-Value Pairs) in a Dictionary in Swift


How to Iterate over Entries (Key-Value Pairs) in a Dictionary in Swift ?

Answer

To iterate over the entries (key-value pairs) in a dictionary in Swift, you can use a `for-in` loop to loop through the dictionary. This allows you to access both the key and the value of each entry.



✐ Examples

1 Iterating over Entries Using a `for-in` Loop

We can iterate over the entries in a dictionary in Swift using a `for-in` loop. This example demonstrates how to loop through the entries of a dictionary and print each key-value pair.

For example,

  1. We start by declaring and initializing a dictionary named myDictionary with integer keys and string values.
  2. We use a `for-in` loop to iterate over the dictionary.
  3. We print each key-value pair inside the loop.

Swift Program

var myDictionary: [Int: String] = [
    1: "One",
    2: "Two",
    3: "Three"
]

// Iterate over the entries in the dictionary
print("Entries in the dictionary:")
for (key, value) in myDictionary {
    print("Key: \(key), Value: \(value)")
}

Output

Entries in the dictionary:
Key: 1, Value: One
Key: 2, Value: Two
Key: 3, Value: Three

2 Iterating over Entries and Performing Operations on Values

We can iterate over the entries in a dictionary in Swift using a `for-in` loop and perform operations on the values. This example demonstrates how to loop through the entries of a dictionary, modify the values, and print each key-value pair.

For example,

  1. We start by declaring and initializing a dictionary named myDictionary with integer keys and string values.
  2. We use a `for-in` loop to iterate over the dictionary.
  3. Inside the loop, we modify the value associated with each key and print the modified key-value pair.

Swift Program

var myDictionary: [Int: String] = [
    1: "One",
    2: "Two",
    3: "Three"
]

// Iterate over the entries in the dictionary and modify values
print("Modified entries in the dictionary:")
for (key, value) in myDictionary {
    let modifiedValue = value.uppercased()
    print("Key: \(key), Value: \(modifiedValue)")
}

Output

Modified entries in the dictionary:
Key: 1, Value: ONE
Key: 2, Value: TWO
Key: 3, Value: THREE

Summary

In this tutorial, we learned How to Iterate over Entries (Key-Value Pairs) in 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 ?