Question

Java Write a Simple Program

This question is about following the directions below. Failure to do so, results in lost credit.

Write the definition of a method that takes in an integer number, and returns true if the number is

prime, otherwise, returns false. A prime number is only divisible by itself and 1. Do not write the code

for main here.

The code must follow these steps in the order shown:

1. Name the method isPrime, and make it take one parameter n as an integer.

2. Decide what the return type must be.

3. Test if n is <= 1, then return false.

4.if the previous step is false, then:

5. Use a for loop, with i as the loop counter, starting at n -1, continuing only if i >= 2, while decrementing

i by 1 each iteration.

6. The for loop body should check if the remainder of dividing n by i is equal to 0. There is an operator

that returns the remainder of division which must be used here. If the remainder of dividing n by i is

equal to 0 then return false - do not do anything otherwise inside the loop.

7. if the for loop ends, return true.

Make sure you have no syntax errors and declare all used variables.

Do not add any other code.

Do not add code for main here.

Now

Write code for main:

1. To get a number from the user via the Console,

2. Then use the isPrime method from the previous question to decide whether the number entered is

prime or not.

3.Display the message "number is prime" if the method isPrime returns true or "number is not prime" if

the isPrime method returns false where number is replaced by the actual value the user entered, to the

Console.

4.Don't forget to declare or prototype the method from the above step.

Answer 1

import java.util.*;

public class Test{

public static boolean isPrime(int number) {

if(number <= 1)

return false;

else {

for(int i = number - 1; i >= 2; i--)

if(number % i == 0)

return false;

return true;

}

}

public static void main(String args[]){

System.out.print("Enter a number: ");

Scanner in = new Scanner(System.in);

int number = in.nextInt();

if(isPrime(number))

System.out.println("Number is prime");

else

System.out.println("Number is not prime");

}

}

Please check the code. If you have any doubts comment below and I am happy to help :)