java math random

1import java.util.Random;
2
3Random rand = new Random();
4
5// Obtain a number between [0 - 49].
6int n = rand.nextInt(50);
7
8// Add 1 to the result to get a number from the required range
9// (i.e., [1 - 50]).
10n += 1;

1int rand = (int)(Math.random() * range) + min; 

1// int rand = (int)(Math.random() * range) + min; 
2// Java program to demonstrate Math.random() working 
3// of java.lang.Math.random() method 
4import java.lang.Math; 
5  
6class Gfg2 { 
7  
8    // driver code 
9    public static void main(String args[]) 
10    { 
11        // define the range 
12        int max = 10; 
13        int min = 1; 
14        int range = max - min + 1; 
15  
16        // generate random numbers within 1 to 10 
17        for (int i = 0; i < 10; i++) { 
18            int rand = (int)(Math.random() * range) + min; 
19  
20            // Output is different everytime this code is executed 
21            System.out.println(rand); 
22        } 
23    } 
24} 

1// Math.random() returns a random number between 0.0-0.99.
2double rnd = Math.random();
3
4// rnd1 is an integer in the range 0-9 (including 9).
5int rnd1 = (int)(Math.random()*10);
6
7// rnd2 is in the range 1-10 (including 10). The parentheses are necessary!
8int rnd2 = (int)(Math.random()*10) + 1;
9
10// rnd3 is in the range 5-10 (including 10). The range is 10-5+1 = 6.
11int rnd3 = (int)(Math.random()*6) + 5;
12
13// rnd4 is in the range -10 up to 9 (including 9). The range is doubled (9 - -10 + 1 = 20) and the minimum is -10.
14int rnd4 = (int)(Math.random()*20) - 10;
15

1(int)(Math.random() * max) + min; inclusive