SwiftでCSV形式の文字列を生成する(Swift2.2)

SwiftでCSV形式の文字列を作成するためのメモ。
カンマが入ったデータにも対応させる。

編集前Ver・・・

var csvData = [
    ["1,234", "222", "hoge", "aaa,bbb,ccc", "1,000,000"],
    [1_000_000, 2, 3, 4, 5.555],
]
var s = ""
for a in csvData {
    for aa in a {
        s += "\"\(aa)\","
    }

    s = s.substringToIndex(s.startIndex.advancedBy(s.characters.count - 1))
    s += "\n"
}
s = s.substringToIndex(s.startIndex.advancedBy(s.characters.count - 1))
print(s)

編集後シンプルVer

var csvData = [
    ["1,234", "222", "hoge", "aaa,bbb,ccc", "1,000,000"],
    [1_000_000, 2, 3, 4, 5.555],
]
var s = csvData.map { $0.map { "\"\($0)\"" }.joinWithSeparator(",") }.joinWithSeparator("\n")
print(s)

結果

"1,234","222","hoge","aaa,bbb,ccc","1,000,000"
"1000000","2","3","4","5.555"