java - 在应用程序启动时强制 scala.Predef 初始化而不影响代码

Question

类的初始化scala.Predef是懒惰的重量级操作，可能会导致应用程序意外减速，并且在时间很重要的情况下（如编程竞赛）会成为麻烦。

val a = new Array[Integer](10)
a(5) = 3 //slowdown on this line

scala.Predef那么我可以在不更改代码的情况下仅使用 scala 编译器或 VM 选项关闭它的惰性并在应用程序启动时强制初始化吗？

Answer 1

No you can't. You can initialize an object by calling it, like this

Predef    // ensures the body of Predef is initialized
val a = new Array[Integer](10)
a(5) = 3

Still, you will probably not have initialized the ArrayOps class which is involved in a.apply. Lazy class initialization is a property of the JVM. If you do benchmarks, that's why you usually give it a "warmup" run first, so that all involved classes have been loaded first.