高阶函数、closure闭包、curry柯里化
// 8-3 结尾闭包（traling closure）和 捕获数值（Capture Values）
import UIKit
var strArr = ["d","cd","bcd","abcd","abc","ab","a"]
sorted(strArr,{(s1,s2) in
if countElements(s1) != countElements(s2)
{
return countElements(s1) < countElements(s2)
}
return s1 < s2
})
//trailing closure
sorted(strArr){(s1,s2) in
if countElements(s1) != countElements(s2)
{
return countElements(s1) < countElements(s2)
}
return s1 < s2
}
