我在 Scala 中有以下代码有效:
var queryMap = Map("name" -> "tim")
age_list.foreach { age => queryMap += ("age" -> age.toString) }
如果我在函数中包含占位符,它会中断:
var queryMap = Map("name" -> "tim")
age_list.foreach { queryMap += ("age" -> _.toString) }
抛出以下错误:
value += is not a member of scala.collection.immutable.Map[String,String]
queryMap 变为不可变 Map 而不是可变 Map。我的语法结构有问题吗?