/// 遍历字符串中每个字符
        for i in <#defaultString#>.characters {
            
            <#content#>
            
        }
        
        let dict = ["key":"value",0: "zero"];
        
        /// 遍历字典
        for (k,v) in <#dict#> {
            
            print("\(k) —— \(v)")
        }

//运行结果:

0 —— zero key —— value