Scala Classic 87th: Using a for expression in Scala to make a query

for (generator; definition; filter) to Do data filtering query

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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Scala Classic 87th: Using a for expression in Scala to make a query