switch-case和if-else的效率比较·必看（上）

public static void main(String[] args) {
        /**
         * switch与if效率测试·测试次数为100W
         */
        int count=1000000;
        Random ra = new Random();
        Runtime r = Runtime.getRuntime();
        r.gc();//计算内存前先垃圾回收一次
        long start = System.currentTimeMillis();
        long startMem = r.freeMemory(); // 开始Memory
        for (int i = 0; i < count; i++) {
            int ch=ra.nextInt(10);
            switch (ch){
                case 0:break;
                case 1:break;
                case 2:break;
                case 3:break;
                case 4:break;
                case 5:break;
                case 6:break;
                case 7:break;
                case 8:break;
                case 9:break;
                default:break;
            }
        }
        long endMem =r.freeMemory(); // 末尾Memory
        long end = System.currentTimeMillis();
        System.out.println("switch判断"+count+"次用时："+(end-start)+"毫秒");
        System.out.println("内存消耗: "+String.valueOf((startMem- endMem)/1024)+"KB");
    }