Write a Java program that uses a value-returning method to identify the prime numbers between 2 bounds (input from the user). The method should identify if a number is prime or not. Call it in a loop for all numbers between the 2 bounds and display only prime numbers. Check for errors in input. Note: A number is prime if it is larger than 1 and it is divisible only by 1 and itself (Note: 1 is NOT a prime number) Example: 15 is NOT prime because 15 is divisible by 1, 3, 5, and 15; 19 is prime because 19 is divisible only by 1 and 19. Sample run: How many times to test for prime numbers? -3 Error! Should be positive. Reenter: 3 Enter lower bound/upper bound: 5 3 Error! Lower bound should be larger. Reenter: 3 15 Prime numbers between 3 and 15 are: 3 5 7 11 13 Enter lower bound/upper bound: 2 25 Prime numbers between 2 and 25 are: 2 3 5 7 11 13 17 19 23 Enter lower bound/upper bound: 1 55 Prime numbers between 1 and 55 are: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53

Respuesta :

Limosa

Answer:

Following are the program in java programming language  

import java.io.*; // import package

import java.util.*; // import package for input

class Main

// main class  

{

  public static int checker(int n)

  {

      int k=2;

      if(n<=1)

          return 0; // return 0

      if(n==2) // this will return 2

          return 1;

      while(k<n) // loop

      {

          if(n%k==0)

              return 0; // return 0

              k++;

      }

      return 1; // return 1

  }

  public static void main(String args[]) // main methid

  {

      int k1=0,j;// variable declaration

      Scanner input1 =new Scanner(System.in); // creating object of scanner class

      System.out.print("How many times to test for prime numbers?");

      int counting=input1.nextInt(); // read the counting

      if(counting<0) // check the condition if countion is less then 0

      {

          System.out.print("Error! Should be positive.Re-enter: ");

          counting=input1.nextInt(); // taking input

      }

      while(k1<counting)

      {

          System.out.print("\nEnter lower bound and upper bound:");

          int lower=input1.nextInt(); // read the lower bound  

          int upper=input1.nextInt(); // read the upper bond

          if(lower>=upper) // check condition  

          {  

              System.out.print("Error! Lower bound should be larger.Reenter: ");

              lower=input1.nextInt();

              upper=input1.nextInt();

          }

          for(j=lower;j<=upper;j++)

          {

              int result=checker(j); // calling functuion checker

              if(result==1)

              System.out.print(j+" ");  

          }

          k1++;

      }

  }

}    

Output:

How many times to test for prime numbers? 1

Enter lower bound and upper bound:  4

8

5 7

Explanation:

  • In this we create a function "checker" of int datatype which return the corresponding prime number .
  • In the main, we taking the user input of upper and lower bound and checking the corresponding conditions which are already mentioned in the question.
  • Call the checker function in the main method which returns the prime number and finally prints the prime numbers between the lower and upper bound.