PHP program to check whether a number prime or not

Karmehavannan

2 years ago

PHP program to check whether a number is prime or not

In this tutorial, we will discuss the concept of the PHP program to check whether a number is prime or not

In this post, we are going to learn how to check whether a number is prime or not, in PHP programming language with Example program.

PHP function to check whether a number is prime or not — Check prime or not

Prime number

The number that can be divided by 1 and itself. it is called a prime number

for Example 2,3,5,7,11,13…

PHP example to check whether a Number is Prime or Not

Check whether the number is prime or not – method 1

In this program, The user declares and initializes variables as positive numbers, then it will check whether the given number is a prime number or not, using the PHP language.

Program 1

<?php
$num=10;
$count=0;
for($i=1; $i<=$num; $i++)
{
if(($num % $i)==0)
{
$count++;
}
}
if($count<3)
{
echo "$num is a prime number";
}
else{
echo "$num is not a prime number";
}
?>

When the above code is executed, it produces the following result

10 is not a prime number

Check whether the number is prime or not – method 2

In this program, The user declares and initializes variables as parameters in the PHP function. When calling the function with an argument then it will check whether the given number is a prime number or not using the PHP function.

Program 2

<?php
function checkPrime($num){
$n=0;
for($i=2; $i<($num/2+1); $i++){
  if($num%$i==0){
  $n++;
  break;
  }
}

if($n==0){
echo $num." is a prime number.";
}else{
echo $num." is not a prime number.";
}
}
checkPrime(11);
?>

When the above code is executed, it produces the following result

11 is a prime number.

Check whether the number is prime or not using a function– method 3

Program 3

<?php
function checkPrime($num){
for($i=2; $i<$num; $i++){
  if($num%$i==0){
  return 0;
  }
}
return 1;
}
$x=checkPrime(27);
if($x==0){
echo "this is not a prime number.";
}else{
echo "this is a prime number.";
}

?>

When the above code is executed, it produces the following result