Random number generation in java

Random generates random numbers (mastery)

• Overview:

  • Random is similar to Scanner, it is also a good API provided by Java, and the function of generating random numbers is provided internally
    • API follow-up courses are explained in detail, and now it can be simply understood as the code that has been written in Java

• Steps for usage:

  1. Import package

     import java.util.Random;

  2. Create object

     Random r = new Random();

  3. Generate random numbers

     int num = r.nextInt (10);

     Explanation: 10 represents a range. If 10 is written in the brackets, the random number generated is 0-9, and 20 is written in the brackets, and the random number of the parameter is 0-19.

• Sample code:

import java.util.Random;

public class Demo1Random {
    
    
	/*
		Random : 产生随机数
		
		1. 导包	: import java.util.Random;
				    导包的动作必须出现在类定义的上面

		2. 创建对象 : Random r = new Random();
					上面这个格式里面，r 是变量名，可以变，其他的都不允许变

		3. 获取随机数 : int number = r.nextInt(10);	//获取数据的范围：[0,10) 包括0,不包括10
					上面这个格式里面，number是变量名，可以变，数字10可以变。其他的都不允许变
		
		需求: 产生随机数1-10之间的
	*/
	public static void main(String[] args){
    
    
		// 2. 创建对象
		Random r = new Random();
		
		for(int i = 1; i <= 10; i++){
    
    
			// 3. 获取随机数
			int num = r.nextInt(10) + 1;		// 1-10
			System.out.println(num);
		}
		
		
		
	}
}