var myString = "Hello world! - swift.jsrun.net" print(myString) for i in 1...9{ var resultString:String = "" for j in 1...i{ if(j== i){//该换行了 resultStr == "\(j) * \(i) = \(j *i)\n" }else { resultStr += "\(j) * \(i) = \(j * i) " } } print(resultStr) } }