Question

Assume $x$ is a double variable, and rand references a Random object. What does the following statement do? x = rand.nextDouble();

Short answer

Answer: The 'nextDouble()' method of a Random object returns a random double value between 0 (inclusive) and 1 (exclusive). The purpose of the Java statement 'x = rand.nextDouble();' is to assign the random double value generated by the 'nextDouble()' method to the variable 'x', storing it for further use in the Java program.

Step-by-step solution

Understand the Random Class and 'nextDouble()' method

In Java, the Random class allows us to generate random numbers. The 'nextDouble()' method is a part of the Random class and it returns a random double value between 0 (inclusive) and 1 (exclusive). Therefore, when calling this method, the returned value will be a double ranging from 0 to just less than 1.

Assign the random value to 'x'

In this step, the statement 'x = rand.nextDouble();' is used to assign the random double value generated by the 'nextDouble()' method to the variable 'x'. This means that after the statement is executed, 'x' will hold a random double value between 0 and just less than 1. The main purpose of this statement is to generate a random double value and store it in the double variable 'x' for further use in the Java program.