关于集合类查找速度
HashMap,Array,List
这三个速度比较是怎样的?
[解决办法]
看来是我错了Array比ArrayList快,我用了个比较简单的例子测试了下Array比ArrayList快了很多~
import java.util.ArrayList;import java.util.Calendar;import java.util.GregorianCalendar;public class TimeTest { public static void main(String[] args) { int[] a = new int[999999]; ArrayList<Integer> b = new ArrayList<Integer>(); for(int i = 0 ; i < 999999;i++){ a[i] = i; b.add(i); } Calendar c = new GregorianCalendar(); long time1 = c.getTimeInMillis(); for(int i = 0 ; i< 999999 ; i++){ if(a[i] == 999998){ break; } } c = new GregorianCalendar(); long time2 = c.getTimeInMillis(); System.out.println("数组查找到999998,所消耗的时间:" + (time2 - time1)); c = new GregorianCalendar(); time1 = c.getTimeInMillis(); for(Integer num : b){ if(num == 999998){ break; } } c = new GregorianCalendar(); time2 = c.getTimeInMillis(); System.out.println("ArrayList查找到999998,所消耗的时间:" + (time2 - time1)); }}