从数组中删除具有重复日期属性的对象

使用日期组件来设置唯一性,因此忽略时间部分

struct Record {
    let date: Date
    let name: String
}

let now = Date()
let soon = Date(timeIntervalSinceNow: 100) 
let future = Calendar.current.date(byAdding: .day, value: 1, to: now)!
let records = [Record(date: now, name: "Now"), 
               Record(date: soon, name: "Soon"),  // same day so should be removed
               Record(date: future, name: "Future")]


var unique = Set<DateComponents>()
let result = records.filter {
    let comps = Calendar.current.dateComponents([.day, .month, .year], from: $0.date)
    if unique.contains(comps) {
        return false
    }
    unique.insert(comps)
    return true
}
print(result)

// [Record(date: 2018-10-11 13:47:17 +0000, name: "Now"),
//  Record(date: 2018-10-12 13:47:17 +0000, name: "Future")]

我的方法与另一个答案类似,但由于使用了 Dictionary 而不是 Array Set 接近。

struct MyObject {
  let startPoint: Date
}

let values: [MyObject] = [...]

let unique = Array(
  values.reduce(into: [Date: MyObject]()) { result, value in
    result[value.startPoint] = result[value.startPoint] ?? value
  }.values
)