如果你想做类似的事情
a(5) = // 一些计算的结果
那么您需要使用可变集合层次结构中的某些内容。我建议ArrayBuffer
.
scala> import scala.collection.mutable.ArrayBuffer
import scala.collection.mutable.ArrayBuffer
scala> val a = ArrayBuffer.fill(3,3)(0)
a: scala.collection.mutable.ArrayBuffer[scala.collection.mutable.ArrayBuffer[Int]] = ArrayBuffer(ArrayBuffer(0, 0, 0), ArrayBuffer(0, 0, 0), ArrayBuffer(0, 0, 0))
scala> a(2)(1) = 4
scala> a(0) = ArrayBuffer(1,2,3)
scala> a
res2: scala.collection.mutable.ArrayBuffer[scala.collection.mutable.ArrayBuffer[Int]] = ArrayBuffer(ArrayBuffer(1, 2, 3), ArrayBuffer(0, 0, 0), ArrayBuffer(0, 4, 0))
注意fill
允许您自动创建和初始化最多 5D 结构。另请注意,您可以扩展这些结构的长度,但它不会扩展整个多维结构,而只会扩展您添加的结构。所以,举例来说,
scala> a(2) += 7 // Add one element to the end of the array
res3: scala.collection.mutable.ArrayBuffer[Int] = ArrayBuffer(0, 4, 0, 7)
scala> a
res4: scala.collection.mutable.ArrayBuffer[scala.collection.mutable.ArrayBuffer[Int]]
= ArrayBuffer(ArrayBuffer(1, 2, 3), ArrayBuffer(0, 0, 0), ArrayBuffer(0, 4, 0, 7))