Generer tilfældigt tal i Java

Java Math.random()-metoden er en matematisk funktion, der bruges til at generere og returnere pseudotilfældige dobbelttypetal med et positivt fortegn, der er større end eller lig med 0,0 og mindre end 1,0

Når vi kalder Math.random(), et java.util.Random pseudorandom-number generator objekt oprettes og bruges.

Math.random() funktionen kan bruges med eller uden videregivelse af parametre. Hvis du angiver parametre, så Math.random() genererer tilfældige tal inden for de givne parametre.

Syntaks

public static double random( )  

Returnering

Denne funktion returnerer pseudotilfældige dobbelttypetal større end eller lig med 0,0 og mindre end 1,0.

Eksempel på Math.random() i Java

//Java Example program for random function of Math Library

//Importing Math Library
import java.lang.Math;

//Public Class
class Main
{
    //main function
    public static void main (String[] args) throws java.lang.Exception
    {
        //Declaring and Initializing the random number of double type
        double randomNumber = Math.random();
        //Printing the captured random number
        System.out.println("Random Number in between 0.0 to 1.0 : " + randomNumber);
    }
} 

OUTPUT:

Random Number in between 0.0 to 1.0: 0.7882868458541263

Eksempel 2

//Importing Math Library
import java.lang.Math;

//Public Class
class Main
{
    //main function
    public static void main (String[] args) throws java.lang.Exception
    {
        //For loop for 10 iterations
        for(int i = 1; i <= 10; i++){
            //Declaring and Initializing the random number of double type
            double randomNumber = Math.random();
            //Printing the captured random number on every iteration
            System.out.println(i+" Random Number in between 0.0 to 1.0 : " + randomNumber);
        }
    }
} 

OUTPUT:

1 Random Number in between 0.0 to 1.0 : 0.3003655151707656
2 Random Number in between 0.0 to 1.0 : 0.7364832919535224
3 Random Number in between 0.0 to 1.0 : 0.9583723106877373
4 Random Number in between 0.0 to 1.0 : 0.35063776440084793
5 Random Number in between 0.0 to 1.0 : 0.10083071735555382
6 Random Number in between 0.0 to 1.0 : 0.958161149095786
7 Random Number in between 0.0 to 1.0 : 0.690570863345631
8 Random Number in between 0.0 to 1.0 : 0.08514487681887206
9 Random Number in between 0.0 to 1.0 : 0.32728295048645895
10 Random Number in between 0.0 to 1.0 : 0.46364767051746814

Java-program til at tilføje 10 tilfældige tal

//Importing Math Library
import java.lang.Math;

//Public Class
class Main
{
    //main function
    public static void main (String[] args) throws java.lang.Exception
    {
        //Declaring an array
        double[] rndList = new double[20];
         //For loop for 10 itterations
        double total = 0;
        for(int i = 1; i <= 10; i++){
            //Declaring and Initializing the random number of double type
            double randomNumber = Math.random();
            //Initilizing captured random number on array's `i` index
            rndList[i] = randomNumber;
        }
        //Using this for loop for adding iteration
        for(int j = 1; j <= 10; j++){
            //Add array value on index `j` with the already got total
            total = rndList[j] + total;
        }
        //printing the value of total
        System.out.println(total);
    }
} 

OUTPUT:

4.867967804651614