Part 1 You will write a program that will determine whether a number is a prime
ID: 3599138 • Letter: P
Question
Part 1
You will write a program that will determine whether a number is a prime number. Allow the user to enter a number, and display a message depending on whether or not it is prime. The user should be allowed to keep entering numbers until they enter “-1” to quit.
Look at Chapter 5, Section 5.11 for some examples working with Prime Numbers.
Part 2
As a second part to this program, allow the user to enter a max number. Then, display each number from 1 to the user-inputted range, as well as whether or not each number is prime.
For example, let’s say the user enters 10 as the max range. The program would show:
1 is prime.
2 is prime.
3 is prime.
4 is not prime.
5 is prime.
6 is not prime.
Explanation / Answer
hey In this Question I am Writing the Code in PHP Language user have to only paste the code and run into the local xampp server with file name index.php
PART B --------------------------------------------
This code is Written in the JAVA
import java.util.Scanner;
/** * Java Program to check if a number is Prime or Not. This program accepts a * number from command prompt //and check if it is prime or not. */
public class Testing { public static void main(String args[]) {
Scanner scnr = new Scanner(System.in);
int number = Integer.MAX_VALUE;
System.out.println("Enter number to check if prime or not ");
while (number != 0) { number = scnr.nextInt();
System.out.printf("Does %d is prime? %s %s %s %n", number, isPrime(number), isPrimeOrNot(number), isPrimeNumber(number));
}
}
/* * Java method to check if an integer number is prime or not. * @return true if number is prime, else false */
public static boolean isPrime(int number)
{
int sqrt = (int) Math.sqrt(number) + 1;
for (int i = 2; i < sqrt; i++)
{
if (number % i == 0)
{
// number is perfectly divisible - no prime
return false;
}
}
return true;
}
/* * Second version of isPrimeNumber method, with improvement like not * checking for division by even number, if its not divisible by 2. */
public static boolean isPrimeNumber(int number)
{
if (number == 2 || number == 3)
{
return true;
}
if (number % 2 == 0) {
return false;
}
int sqrt = (int) Math.sqrt(number) + 1;
for (int i = 3; i < sqrt; i += 2) {
if (number % i == 0)
{
return false;
}
}
return true;
}
/* * Third way to check if a number is prime or not. */
public static String isPrimeOrNot(int num) {
if (num < 0)
{
return "not valid";
}
if (num == 0 || num == 1) {
return "not prime";
}
if (num == 2 || num == 3) {
return "prime number";
}
if ((num * num - 1) % 24 == 0) {
return "prime";
}
else
{
return "not prime";
}
}
}
Output
Enter number to check if prime or not
2? Does 2 is prime? true prime number true
3? Does 3 is prime? true prime number true
4? Does 4 is prime? false not prime false
5? Does 5 is prime? true prime true
6? Does 6 is prime? false not prime false
7? Does 7 is prime? true prime true
17? Does 17 is prime? true prime true
21? Does 21 is prime? false not prime false
131? Does 131 is prime? true prime true
139? Does 139 is prime? true prime true