Swift - 区间运算符（... 和 ..<）

for icount in 512...1024 {
            print(icount)//从512遍历到1024（包括1024）
        }

et fruts = ["apple","orange","banana"]
        let icount = fruts.count
        for i in 0..<icount {
            print("第\(i+1)个水果是\(fruts[i])")
        }

//字符串截取
        let words = "hhggll.com"
        
        //不使用区间运算符
        let index = words.startIndex.advancedBy(3)
        let index2 = words.startIndex.advancedBy(6)
        let range1 = Range<String.Index>(start: index, end: index2)
        let rangeStr1 = words.substringWithRange(range1)
        print(rangeStr1)
        
        
        //使用区间运算符
        let range2 = words.startIndex.advancedBy(3)..<words.startIndex.advancedBy(6)
        let rangeStr2 = words.substringWithRange(range2)
        print(rangeStr2)
        
        let hWords = "Hhggll.com"
        let interval = "a"..."z"
        for c in hWords.characters {
            if !interval.contains(String(c)) {
                print("\(c)不是小写字母")
            }
            
        }