The **`Math.random()` method** returns a pseudorandom number of data type `double`. The range of this random number is given by the following limit:

>$0.0\leq x  <1.0$                                
>where $x$ is the random number.

This method belongs to the `java.lang.Math` class, so you need to import this class before implementing​ this method. 


Using the code snippet below we can generate a random number of type `double`. Give it a try!

import java.lang.Math; //importing Math class in Java

class MyClass { 
  public static void main(String args[]) 
  { 
    double rand = Math.random(); // generating random number 
    System.out.println("Random Number: " + rand);  // Output is different everytime this code is executed 
  } 
} 

# Using random() method for a range
Mostly the `random()` method is used to generate random numbers between a specific range. Using this method, we define a method named `randomWithRange`, that returns an integer with a user-defined range.

int randomWithRange(int min, int max){
   int range = (max - min) + 1;     
   return (int)(Math.random() * range) + min;
}

Since the `random()` method produces a `double` number, we need to cast it in an integer, just as shown in the example below:

class MyClass {
  int randomWithRange(int min, int max){   //defining method for a random number generator

    int range = (max - min) + 1;     
    return (int)(Math.random() * range) + min;
  }  
  public static void main( String args[] ) {
    MyClass obj1=new MyClass();       // creating an object of MyClass
    int rand=obj1.randomWithRange(1,100); // range is from 1 to 100 
    System.out.println(rand);
  }
}

How to use the Math.random() method in Java

Math.random() returns a pseudorandom double between 0.0 and 1.0. It requires importing java.lang.Math.