Question

I have an array of dictionaries called groupedDictionary defined below:

// The type is [String : [SingleRepository]]
let groupedDictionary = Dictionary(grouping: finalArrayUnwrapped) { (object) -> String in
        var language = "Not Known to GitHub"
        if let languageUnwrapped = object.language {
            language = languageUnwrapped
        }

        return language
    }

I can easily get all the keys as follows:

let keys = groupedDictionary.keys

However, when I try to sort this array using sorted(by:) in Swift 4, I successfully get the sorted array back with the type [(key: String, value: [SingleRepository])].

// the type is [(key: String, value: [SingleRepository])]
    let sortedGroupedDictionary =  groupedDictionary.sorted(by: { ($0.value.count) > ($1.value.count) })

How can I get all of the keys from sortedGroupedDictionary?

It is not possible to call ".keys" on sortedGroupedDictionary, since it has a different type.

Please note: I'm not trying to sort the array based on the keys. I did sort the array that consists of dictionaries, based on a predicate which is size of the array containing each value, now I just want to extract the keys.

Answer 1

方法$ find . -type f $ -iname \*.js -o -iname \*.css $ -exec gzip -9 "{}" \; -exec mv "{}.gz" "{}" \; -exec sed 's#^./##' "{}" \;以键-值对数组的形式返回原始字典的键和值，并按您作为参数传递的谓词进行排序。这意味着每个元组的第一个元素就是您要查找的键。

您可以像这样查看结果：

Dictionary.sorted(by:)

如果您需要的只是一组排序键，则可以使用

for (key, value) in sortedGroupedDictionary {
    // handle this key-value-pair
}

accessing keys from a returned sorted array of dictionaries in Swift 4

1 个答案: