Write a program in Php to check whether a number is prime or not

 A prime number is a number that can only be divided by itself and 1 without remainders. Here we explain what exactly this means, give you a list of the prime numbers children need to know at primary school and provide you with some practice prime number questions and examples.

What is a prime number?

A prime number is a number greater than 1 with only two factors – themselves and 1.

A prime number cannot be divided by any other numbers without leaving a remainder.

An example of a prime number is 13. It can only be divided by 1 and 13. Dividing a prime number by another number results in numbers left over e.g. 13 ÷ 6 = 2 remainder 1.

15 is not an example of a prime number because it can be divided by 5 and 3 as well as by itself and 1.

15 is an example of a composite number because it has more than two factors.

PHP Program for Check if a number is prime

<?php

// PHP code to check whether a number is prime or Not

// function to check the number is Prime or Not

function primeCheck($number){

if ($number == 1) 

return 0;

for ($i = 2; $i <= $number/2; $i++){

if ($number % $i == 0)

return 0;

}

return 1;

}

// Driver Code

$number = 31;

$flag = primeCheck($number);

if ($flag == 1)

echo "Prime";

else

echo "Not Prime"

?>