按键值对字典排序 [英] Sort Dictionary by Key Value
本文介绍了按键值对字典排序的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
let dict: [String:Int] = ["apple":5, "pear":9, "grape":1]
如何根据Int
值对字典进行排序,以使输出为:
How do you sort the dictionary based on the Int
value so that the output is:
sortedDict = ["pear":9, "apple":5, "grape":1]
当前尝试(排序不正确):
let sortedDict = sorted(dict) { $0.1 > $1.1 }
推荐答案
您需要对字典值而不是键进行排序.您可以从字典中创建一个元组数组,按其值对它进行排序,如下所示:
You need to sort your dictionary values, not your keys. You can create an array of tuples from your dictionary sorting it by its values as follow:
Xcode 9•Swift 4 或 Xcode 8•Swift 3
let fruitsDict = ["apple": 5, "pear": 9, "grape": 1]
let fruitsTupleArray = fruitsDict.sorted{ $0.value > $1.value }
fruitsTupleArray // [(.0 "pear", .1 9), (.0 "apple", .1 5), (.0 "grape", .1 1)]
for (fruit,votes) in fruitsTupleArray {
print(fruit,votes)
}
fruitsTupleArray.first?.key // "pear"
fruitsTupleArray.first?.value // 9
使用键对字典进行排序
To sort your dictionary using your keys
let fruitsTupleArray = fruitsDict.sorted{ $0.key > $1.key }
fruitsTupleArray // [(key "pear", value 9), (key "grape", value 1), (key "apple", value 5)]
要使用字典的键和本地化的比较来对字典进行排序:
To sort your dictionary using its keys and localized comparison:
let fruitsTupleArray = fruitsDict.sorted { $0.key.localizedCompare($1.key) == .orderedAscending }
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