过滤和排序快速数组

Question

我有一个要过滤的快速数组，这是数组

let array = [apple,workshops,shopping,sports,parties,pantry,pen] 

我想过滤数组，使以搜索字符串开头的项目出现在仅包含搜索字符串的项目之前

所以当我搜索例如p时，结果应该以某种方式

let array = [parties,pantry,pen,apple,workshops,shopping,sports] 

我试过了

tagSearchResults = tagSearchResults.filter({ (interestTag:InterestTag) -> Bool in
            let tmp: NSString = interestTag.tag
            let range = tmp.rangeOfString(searchText, options: NSStringCompareOptions.CaseInsensitiveSearch)
            return range.location != NSNotFound
        })

但这给了我所有包含搜索字符串的字符串。

伙计们我该怎么做

Answer 1

你可以写

 let result = words
    .filter { $0.contains(keyword) }
    .sorted { ($0.hasPrefix(keyword) ? 0 : 1) < ($1.hasPrefix(keyword) ? 0 : 1) }

例

let words = ["apple", "workshops", "shopping", "sports", "parties", "pantry", "pen", "cat", "house"]
let keyword = "p"
let result = words
    .filter { $0.contains(keyword) }
    .sorted { ($0.hasPrefix(keyword) ? 0 : 1) < ($1.hasPrefix(keyword) ? 0 : 1) }

// ["pen", "pantry", "parties", "apple", "workshops", "shopping", "sports"]

Answer 2

尝试这个。 首先，它过滤数组以删除不包含搜索字符串的那些元素，然后使用自定义排序来偏爱以搜索字符串开头的项目。 通常，使用笛卡尔方法将问题分解为较小的子问题，而不是尝试一步一步解决所有问题。

let searchString = "p"
let array = ["apple", "workshops", "shopping", "sports", "parties", "pantry", "pen", "xyzzy"]

let filteredArray = array.filter({ $0.contains(searchString) })
filteredArray // drops xyzzy

let sortedArray = filteredArray.sorted(isOrderedBefore:  {
    switch ($0.hasPrefix(searchString), $1.hasPrefix(searchString)) {
    case (true, true):
        return $0 < $1
    case (true, false):
        return true
    case (false, true):
        return false
    case (false, false):
        return $0 < $1
    }

})
sortedArray // "pantry", "parties", "pen", "apple", "shopping", "sports", "workshops"] as required

Answer 3

其它的办法：

let searchString = "p"
let array = ["apple", "workshops", "shopping", "sports", "parties", "pantry", "pen", "xyzzy"]
let result = array.filter{$0.containsString(searchString)}
    .map{($0.hasPrefix(searchString) ? 0 : 1, $0)}
    .sort{$0 < $1}
    .map{$1}
print(result) //->["pantry", "parties", "pen", "apple", "shopping", "sports", "workshops"]

（我不知道为什么，但是我的Xcode花了很多时间来编译这些行。相信这个编译并最终会按预期运行。）