Swift语言过滤
示例
通过从流中选择通过特定条件的元素来创建流称为过滤
var newReleases = [
[
"id": 70111470,
"title": "Die Hard",
"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
"rating": 4.0,
"bookmark": []
],
[
"id": 654356453,
"title": "Bad Boys",
"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
"rating": 5.0,
"bookmark": [[ "id": 432534, "time": 65876586 ]]
],
[
"id": 65432445,
"title": "The Chamber",
"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
"rating": 4.0,
"bookmark": []
],
[
"id": 675465,
"title": "Fracture",
"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
"rating": 5.0,
"bookmark": [[ "id": 432534, "time": 65876586 ]]
]
]
var videos1 = [[String: AnyObject]]()
/**
* Filtering using map
*/
newReleases.map { e in
if e["rating"] as! Float == 5.0 {
videos1.append(["id": e["id"] as! Int, "title": e["title"] as! String])
}
}
print(videos1)
var videos2 = [[String: AnyObject]]()
/**
* Filtering using filter and chaining
*/
newReleases
.filter{ e in
e["rating"] as! Float == 5.0
}
.map { e in
videos2.append(["id": e["id"] as! Int, "title": e["title"] as! String])
}
print(videos2)