Java Math.random() method

DevSniper
Published : 16 June 2024

150 Views

public static double random( )

Math.random() return a double number between 0.0 to 1.0 (range [0.0, 1.0)).
if you want to generate a random number between a range you can do this by multiplying the return value with the magnitude of the range

Example 1

Java Math.random() will return random number between range [0.0,1.0) so output will change for every run.

public class Program
{

     public static void main(String []args)
     {
        System.out.println("Math.random() : "+Math.random());
        System.out.println("Math.random() : "+Math.random());
        System.out.println("Math.random() : "+Math.random());
        System.out.println("Math.random() : "+Math.random());
        System.out.println("Math.random() : "+Math.random());
     }
}

Math.random() : 0.9891889028135935
Math.random() : 0.4286327285015362
Math.random() : 0.28544320094692466
Math.random() : 0.6280691106902716
Math.random() : 0.9648010857547152

Example 2

Generating number between range [a,b)

public class Program
{

     public static void main(String []args)
     {
        int a=5;
        int b=10;
        System.out.println("Number range[5,10) : "+(a+Math.random()*b));
        System.out.println("Number range[5,10) : "+(a+Math.random()*b));
        System.out.println("Number range[5,10) : "+(a+Math.random()*b));
        System.out.println("Number range[5,10) : "+(a+Math.random()*b));
        System.out.println("Number range[5,10) : "+(a+Math.random()*b));
        System.out.println("Number range[5,10) : "+(a+Math.random()*b));
     }
}

Number range[5,10) : 8.84234278157376
Number range[5,10) : 6.431909562551892
Number range[5,10) : 14.725129578055908
Number range[5,10) : 7.798699456954674
Number range[5,10) : 10.318125214908372
Number range[5,10) : 9.495319180234429