How can I get key's value from dictionary in Swift?

Question

I have a Swift dictionary. I want to get my key's value. Object for key method is not working for me. How do you get the value for a dictionary's key?

This is my dictionary:

var companies = ["AAPL" : "Apple Inc", "GOOG" : "Google Inc", "AMZN" : "Amazon.com, Inc", "FB" : "Facebook Inc"]  for name in companies.keys {      print(companies.objectForKey("AAPL")) } 

Answer 1

Use subscripting to access the value for a dictionary key. This will return an Optional:

let apple: String? = companies["AAPL"] 

or

if let apple = companies["AAPL"] {     // ... } 

---

You can also enumerate over all of the keys and values:

var companies = ["AAPL" : "Apple Inc", "GOOG" : "Google Inc", "AMZN" : "Amazon.com, Inc", "FB" : "Facebook Inc"]  for (key, value) in companies {     print("\(key) -> \(value)") } 

Or enumerate over all of the values:

for value in Array(companies.values) {     print("\(value)") } 

Answer 2

From Apple Docs

You can use subscript syntax to retrieve a value from the dictionary for a particular key. Because it is possible to request a key for which no value exists, a dictionary’s subscript returns an optional value of the dictionary’s value type. If the dictionary contains a value for the requested key, the subscript returns an optional value containing the existing value for that key. Otherwise, the subscript returns nil:

https://developer.apple.com/documentation/swift/dictionary

if let airportName = airports["DUB"] {     print("The name of the airport is \(airportName).") } else {     print("That airport is not in the airports dictionary.") } // prints "The name of the airport is Dublin Airport."