Java中double和float哪个快

作者: twd2 日期: 2013 年 12 月 27 日被围观 319 次发表评论 (2) 查看评论

撰写代码如下

public class Main {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO 自动生成的方法存根
        double a,b;
        a=test1(10);
        b=test2(10);
        System.out.println(a);
        System.out.println(b);
        System.out.println(b/a);
    }
 
    public static double test1(int n)
    {
        double total=0.0;
        double t=0.0d;
        for (int i=0;i<n;++i){
            long t0,t1,t2;
            t0=System.nanoTime();
            t1=System.nanoTime();
            for(int j=0;j<100000000;++j) {
                t+=0.1d;
            }
            t2=System.nanoTime();
            total+=t2-t1-(t1-t0);
        }
        return total/n;
    }
 
    public static double test2(int n)
    {
        double total=0.0;
        float t=0.0f;
        for (int i=0;i<n;++i){
            long t0,t1,t2;
            t0=System.nanoTime();
            t1=System.nanoTime();
            for(int j=0;j<100000000;++j) {
                t+=0.1f;
            }
            t2=System.nanoTime();
            total+=t2-t1-(t1-t0);
        }
        return total/n;
    }
 
}