重复
scala> "hello" * 5 res20: String = hellohellohellohellohello
切分
scala> "hello jihao ni shijie en".split(" +") res108: Array[String] = Array(hello, jihao, ni, shijie, en)
9-2 String
渐变 --> 突变
重复
scala> "hello" * 5 res20: String = hellohellohellohellohello
切分
scala> "hello jihao ni shijie en".split(" +") res108: Array[String] = Array(hello, jihao, ni, shijie, en)