逛奔的蝸牛

long startTime;

long endTime;

int times = 8000000;

Random rand = new Random();

startTime = System.currentTimeMillis();

for (int i = 0; i < times; i++) {

int a = rand.nextInt(5);

//System.out.println(a);

}

endTime = System.currentTimeMillis();

System.out.println("Random.nextInt(): " + (endTime - startTime));

startTime = System.currentTimeMillis();

for (int i = 0; i < times; i++) {

int a = (int)(Math.random() * 5);

}

endTime = System.currentTimeMillis();

System.out.println("Math.random(): " + (endTime - startTime));