我有Array
:
let myArray = [String]()
我想添加一个didSet { }
,它知道实际更改的数组索引。
答案 0 :(得分:0)
你可以试试这个 -
let myArray = [String]()
class YourClassName
{
var array = [1,2,3,4,5]
{
didSet
{
let changedIndexes = zip(array, myArray).map{$0 != $1}.enumerated().filter{$1}.map{$0.0}
print("Changed indexes: \(changedIndexes)")
}
}
}
let demo = YourClassName()
demo.array = [1,2,7,7,5]
// prints: Changed indexes: [2, 3]
答案 1 :(得分:0)
这将为您提供所有已更改的索引,即使这些数组具有不同的长度:
class TestClass {
var array: [String] = ["a", "2", "3", "d", "5", "has one more"] {
didSet {
var changed = zip(array, oldValue).enumerated().reduce([]) { $1.element.0 == $1.element.1 ? $0 : $0 + [$1.offset] }
changed.append(Array(min(array.count, oldValue.count)..<max(array.count, oldValue.count)))
print(changed) // prints: [0, 3, 5]
}
}
}
TestClass().array = ["1", "2", "3", "4", "5"]
第一行:
var changed = zip(array, oldValue).enumerated().reduce([]) { $1.element.0 == $1.element.1 ? $0 : $0 + [$1.offset] }
获取所有索引,直到最短数组结束时不同,第二行:
changed.append(Array(min(array.count, oldValue.count)..<max(array.count, oldValue.count)))
附加较长数组的其余索引。