How to Sort an Array of NSDictionary using DateTim

问题:

I have an NSArray of NSDictionary

let Array = (
{ name = "Auni";
  age = "24";
  transactionTime = "01-02-2011 12:32:39" },
{ name = "Atiqah";
  age = "23";
  transactionTime = "02-02-2013 10:32:41" },
{ name = "Aida";
  age = "22";
  transactionTime = "04-02-2020 18:32:21"})

How do I sort this array by most recent transactionTime? Using Swift4.

Thank you.

Edit: It's easier to have back-end people do it for you.

回答1:

You do not need to convert into Date object, dateStrings direct comparison will also work.

array.sort { (dict1, dict2) -> Bool in

    /// Considering "transactionTime" key always exists.
    let transactionTime1 = dict1["transactionTime"]!
    let transactionTime2 = dict2["transactionTime"]!

    /// Sort in descending order
    return transactionTime1 > transactionTime2
}

In case you need some calculation on date objects then You can also convert the string into date objects at run time like below example:

let df = DateFormatter()
df.dateFormat = "dd-MM-yyyy HH:mm:ss"
array.sort { (dict1, dict2) -> Bool in

    /// Considering "transactionTime" key always exists.
    let transactionTime1 = dict1["transactionTime"]!
    let transactionTime2 = dict2["transactionTime"]!

    let date1 = df.date(from: transactionTime1)!
    let date2 = df.date(from: transactionTime2)!

    /// Sort in descending order
    return date1 > date2
}

print(array)

Output

[["transactionTime": "04-02-2020 18:32:21", "name": "Aida", "age": "22"], ["transactionTime": "02-02-2013 10:32:41", "name": "Atiqah", "age": "23"], ["transactionTime": "01-02-2011 12:32:39", "name": "Auni", "age": "24"]]