<> Generate random number
subject ：
generate 100 individual 1 reach 6 Random integer , Statistics 1~6 Probability of occurrence of each number
Method 1 ：
use java.util.Math
Math Class has a static method ：random(), generate double Random number of type （ Range ：[0.0~1.0) barring 1）
Modifier and TypeMethodDescription
static doublerandom() generate double Random number of type （ Range ：[0.0~1.0) barring 1）
How to generate 1~6 Random integer ?
int x=(int)(Math.random()*6+1); Math.random()*6 The scope is [0.0-6.0) barring 6 Math.random(
)*6+1 The scope is [1.0-7.0) barring 7 But there is a cast double-->int, therefore 6.7 Will be converted to 6
code ：
public class CreatRandom1 { public static void main(String[] args) { int[] arr1
=new int[100]; int[] arr2=new int[7]; for (int i = 0; i < arr1.length; i++) {
arr1[i]=(int)(Math.random()*6+1); arr2[arr1[i]]++; } for (int j = 1; j < arr2.
length; j++) { System.out.println(j+" The number appears :"+arr2[j]+" second "); } } }
Method 2 ：
use java.util.Random
Random Class nextInt(int bound), generate 0.0 To a random integer in the specified range
Modifier and TypeMethodDescription
intnextInt(int bound) Generate random integer （ Range ：[0.0~bound) barring bound）
How to generate 1~6 Random integer ?
Random random=new Random(); int x=random.nextInt(6)+1; random.nextInt(6) Range ：[
0.0-6.0) barring 6 random.nextInt(6)+1 Range ：[1.0-7.0) barring 7,int type , image 6.6 Such a number is 6. Other codes are the same as above
<> How to generate other types of random numbers , Please read another article java.util.Random.
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