Question

在许多网站中我研究过scala比Java快。我编写了代码来测试这两者之间的时差，但Scala需要更多时间。我不知道自己是否犯了任何错误。如果我错了，请纠正我。

Scala代码

package com.first

import java.util.ArrayList

object Word extends App{
  val absoluteResult = new ArrayList[Any]()
  val before = System.currentTimeMillis()
  var i =0
  while (i<10000) {
    i = i+1
    val result = List("foo", 23, true).iterator
    while (result.hasNext) {
      absoluteResult.add(foo(result.next))
    }
  }
  println("Took : "+(System.currentTimeMillis() - before)
      +" ms, number of elements : "+absoluteResult.size)

  def foo(obj : Any) =
    obj match {
          case _:String => "String"
          case _:Boolean => "Boolean"
          case _:Integer => "Integer"
          case _ => throw new IllegalArgumentException()
    }
}

输出采取：142毫秒，元素数量：30000

Java代码

package com.first;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class quicksort {
    public static void main(String[] args) {
        List<Object> absoluteResult = new ArrayList<Object>();
        long before = System.currentTimeMillis();
        for (int i=0; i < 10000; i++) {
          List<Object> result = new ArrayList<Object>();
          result.add("foo");
          result.add( 23);
          result.add(true);
          for (Object y : result) {
            absoluteResult.add(foo(y));
          }
        }
        System.out.println("Took : "+(System.currentTimeMillis() - before)
          +" ms, number of elements : "+absoluteResult.size());
      }


    static String foo(Object s) {
      if (s instanceof String) {
        return "String";
      } else if (s instanceof Boolean) {
        return "Boolean";
      } else if (s instanceof Integer) {
        return "Integer";
      } else {
        throw new IllegalArgumentException();
      }
}
}

输出采取：30毫秒，元素数量：30000

scala是否比java在JVM上运行更快？

0 个答案: