Arrays 如何将字典键和值(字符串/数组)映射到swift中的一个字符串
我有一本字典,看起来像:Arrays 如何将字典键和值(字符串/数组)映射到swift中的一个字符串,arrays,dictionary,swift3,Arrays,Dictionary,Swift3,我有一本字典,看起来像: ["foo": "whatever", "this": "that", "category": ["cat1", "cat2"]] 我需要它是一个字符串,比如: foo=whatever&this=that&category=cat1&category=cat2 因此,如果一个键具有数组类型的值,那么该键应该在字符串中出现多次。如果您知道字典类型,我相信类似的方法应该有效: var string = "" for key in dict.ke
["foo": "whatever", "this": "that", "category": ["cat1", "cat2"]]
我需要它是一个字符串,比如:
foo=whatever&this=that&category=cat1&category=cat2
因此,如果一个键具有数组类型的值,那么该键应该在字符串中出现多次。如果您知道字典类型,我相信类似的方法应该有效:
var string = ""
for key in dict.keys {
if let array = dict[key] as? [String] {
for arrayItem in array {
string += "\(key)=\(arrayItem)&"
}
}
else if let value = dict[key] as? String {
string += "\(key)=\(value)&"
}
}
print(string.substring(to: string.index(before: string.endIndex)))
注意,这可能会以随机顺序打印它们,因为字典没有排序如果您知道字典类型,我相信类似的方法应该会起作用:
var string = ""
for key in dict.keys {
if let array = dict[key] as? [String] {
for arrayItem in array {
string += "\(key)=\(arrayItem)&"
}
}
else if let value = dict[key] as? String {
string += "\(key)=\(value)&"
}
}
print(string.substring(to: string.index(before: string.endIndex)))
注意,这可能会以随机顺序打印它们,因为字典没有按Alexander建议的顺序排序,这是一种使用
URLComponents
和URLQueryItem
import Foundation
let dict: [String: Any] = [
"foo": "whatever",
"this": "that",
"category": [
"cat1",
"cat2"
]
]
var queryItems = [URLQueryItem]()
for (key, value) in dict {
if let strings = value as? [String] {
queryItems.append(contentsOf: strings.map{ URLQueryItem(name: key, value: $0) })
} else {
queryItems.append(URLQueryItem(name: key, value: value as? String))
}
}
var urlComponents = URLComponents(string: "http://myserver.com")!
urlComponents.queryItems = queryItems
let url = urlComponents.url!
print(url.absoluteString) // => http://myserver.com?this=that&foo=whatever&category=cat1&category=cat2
类似的解决方案,但更简单,使用flatMap
:
let queryItems = dict.flatMap { key, value -> [URLQueryItem] in
if let strings = value as? [String] {
return strings.map{ URLQueryItem(name: key, value: $0) }
} else {
return [URLQueryItem(name: key, value: value as? String)]
}
}
var urlComponents = URLComponents(string: "http://myserver.com")!
urlComponents.queryItems = queryItems
let url = urlComponents.url!
print(url.absoluteString) // => http://myserver.com?this=that&foo=whatever&category=cat1&category=cat2
正如Alexander所建议的,这是一个包含
URLComponents
和URLQueryItem
import Foundation
let dict: [String: Any] = [
"foo": "whatever",
"this": "that",
"category": [
"cat1",
"cat2"
]
]
var queryItems = [URLQueryItem]()
for (key, value) in dict {
if let strings = value as? [String] {
queryItems.append(contentsOf: strings.map{ URLQueryItem(name: key, value: $0) })
} else {
queryItems.append(URLQueryItem(name: key, value: value as? String))
}
}
var urlComponents = URLComponents(string: "http://myserver.com")!
urlComponents.queryItems = queryItems
let url = urlComponents.url!
print(url.absoluteString) // => http://myserver.com?this=that&foo=whatever&category=cat1&category=cat2
类似的解决方案,但更简单,使用flatMap
:
let queryItems = dict.flatMap { key, value -> [URLQueryItem] in
if let strings = value as? [String] {
return strings.map{ URLQueryItem(name: key, value: $0) }
} else {
return [URLQueryItem(name: key, value: value as? String)]
}
}
var urlComponents = URLComponents(string: "http://myserver.com")!
urlComponents.queryItems = queryItems
let url = urlComponents.url!
print(url.absoluteString) // => http://myserver.com?this=that&foo=whatever&category=cat1&category=cat2
谢谢你。顺序是不相关的,也许是一个更快速的方法,一些地图或平面地图?谢谢。顺序是不相关的,可能是更快速的方法,使用map或flatmap?您应该查看
NSURLComponents
和NSQueryItem
。它正是您想要的:您应该查看NSURLComponents
和NSQueryItem
。它正是您想要的:编辑为使用条件绑定而不是is
+as
我是否也应该编辑以在重复的附录上使用映射
?@Alexander继续:-)@Alexander非常感谢。编辑以使用条件绑定而不是是
+as
我是否也应该编辑以在重复的附录上使用映射
?@Alexander继续:-)@Alexander非常感谢。