Generate a random number using JavaSE.

Generate a random number using JavaSE.

Today, the instructor talked about how to use jvm to implement random numbers (I am very interested in this). A simple code for random integers less than 100 is as follows:

/** Generate random number */import java. util. random; public class Random01 {int I; public static void main (String [] args) {// create a Random number generator Random r = new Random (); // generate a random number of the int type // int I = r. nextInt (101); // Random Number of [0-100] // System. out. println (I); for (int I = 0; I <5; ++ I) {System. out. println (r. nextInt (101 ));}}}

/** Generate random number */import java. util. random; public class Random01 {int I; public static void main (String [] args) {// create a Random number generator Random r = new Random (); // generate a random number of the int type // int I = r. nextInt (101); // Random Number of [0-100] // System. out. println (I); for (int I = 0; I <5; ++ I) {System. out. println (r. nextInt (101 ));}}}

Then the teacher assigned a new requirement: Write a random integer of less than 100, and it cannot be repeated. After thinking about it, write it like this:

import java.util.*;public class suiji{    public static void main(String[] args){        Random aa = new Random();        ArrayList list = new ArrayList();        for(int i=0; i< 5 ; ++i){            list.add(aa.nextInt(101));            for(int k=0; k < i; ++k){                if(list.get(i).equals(list.get(k))){                    list.remove(i);                    i--;                }            }            System.out.println( aa.nextInt(101) );        }    }}

import java.util.*;public class suiji{    public static void main(String[] args){        Random aa = new Random();        ArrayList list = new ArrayList();        for(int i=0; i< 5 ; ++i){            list.add(aa.nextInt(101));            for(int k=0; k < i; ++k){                if(list.get(i).equals(list.get(k))){                    list.remove(i);                    i--;                }            }            System.out.println( aa.nextInt(101) );        }    }}

Please make an axe.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~ Jie Li Education