如何按两个字段对Scala中的列表进行排序? [英] How to sort a list in Scala by two fields?

问题描述

如何在 Scala 中按两个字段对列表进行排序，在此示例中我将按 lastName 和 firstName 排序?

how to sort a list in Scala by two fields, in this example I will sort by lastName and firstName?

case class Row(var firstName: String, var lastName: String, var city: String)

var rows = List(new Row("Oscar", "Wilde", "London"),
                new Row("Otto",  "Swift", "Berlin"),
                new Row("Carl",  "Swift", "Paris"),
                new Row("Hans",  "Swift", "Dublin"),
                new Row("Hugo",  "Swift", "Sligo"))

rows.sortBy(_.lastName)

我尝试这样的事情

rows.sortBy(_.lastName + _.firstName)

但它不起作用.所以我很好奇一个好的和简单的解决方案.

but it doesn't work. So I be curious for a good and easy solution.

推荐答案

rows.sortBy(r => (r.lastName, r.firstName))

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