for(生成器;定义;过滤器) 来做数据过滤查询
package com.dt.scala.forexpression
case class Book(title : String , authors : List[String])
object For_Query {
def main(args: Array[String]) {
val books: List[Book] = List(
Book("Structure and Interpretation ", List("Abelson , Harold", "Sussman")),
Book("Principles of Compiler Design",
List("Aho, Alfred", "Ullman, Jeffrey")),
Book("Programming in Modula-2", List("Wirth, Niklaus")),
Book("Introduction to Functional Programming", List("Bird, Richard")),
Book("The Java Language Specification",
List("Gosling, James", "Joy, Bill", "Steele, Guy", "Bracha, Gilad")))
// val result = for(b <- books ; a <- b.authors if a startsWith "Gosling") yield b.title
val result = for(b <- books if (b.title indexOf "Programming") >= 0 ) yield b.title
println(result)
}
}
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