java 隨機 亂數

public static void main(String[] args) {
Random rand = new Random();
int a = rand.nextInt(5);//0,1,2,3,4 從0開始找出5個數
int b = rand.nextInt(5)+10;//10,11,12,13,14 從10開始找出5個數
System.out.print(a);
System.out.print(b);
}
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public int getRandom(){
Random rand = new Random();
rand.setSeed(System.currentTimeMillis());
System.out.println("Boolean => "+rand.nextBoolean());
System.out.println("Double => "+rand.nextDouble());
System.out.println("Float => "+rand.nextFloat());
System.out.println("Gaussian=> "+rand.nextGaussian());
System.out.println("Int => "+rand.nextInt());
System.out.println("Int(5) => "+rand.nextInt(5));
System.out.println("Long => "+rand.nextLong());
return 0;
}
result:
Boolean => false
Double => 0.21165203005812516
Float => 0.45669615
Gaussian=> -1.1126663932933862
Int => -1475214918
Int(5) => 2
Long => -7153134665631835287