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iOS Swift Basics (retired) Collections What is a Dictionary?

Posted by ingavelikanova
ingavelikanova
4,528 Points

Hi I have difficulty with dictionaries in swift ,I am not sure I understand the assignment .it is chalenge task 2

I added code but it doesn't compile

dictionaries.swift 
let currencies = [ "US" : "Dollar" , "UK" : "Pound" , "JP" : "Yen" ];

 let ukCurrency = ["UK"];

1 Answer

Alvin Abia
PLUS
Alvin Abia
Courses Plus Student 23,034 Points
Alvin Abia
Alvin Abia
Courses Plus Student 23,034 Points

Hey Inga, the good news is that the issue I think you're facing is a relatively simple one to fix. When you are creating a dictionary as you did here (I am just spacing your code a little differently for explanation's sake):

let currencies = [ 
    "US" : "Dollar" , 
    "UK" : "Pound" , 
    "JP" : "Yen" 
]

The first strings before the colon ("US", "UK", "JP") are the keys. The second strings after the colon ("Dollar", "Pound", "Yen") are the values/objects you are setting to the respective keys.

If you are trying to access the value/object for a specific key (such as accessing "Pound" above), you would type in the array's name followed by square brackets containing its respective key as a string.

let ukCurrency = currencies["UK"]

This above line of code is basically declaring a constant named ukCurrency that will hold whatever is the value for the key "UK" in the currencies array. Hope this answer helps, let me know how it goes!