PHP| Check if a number is prime or not

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PHP| Check if a number is prime or not

In this article, we will discuss the concept of the PHP| Check if a number is prime or not

In this post, we are going to learn how to write a program to check whether the given number is prime or not and display the result on the screen in the PHP programming language.

Code to check prime number

Check the prime number in PHP – #1

In this program, the user initiates the values to variables “num” as 11 and “count” as 0, and the program checks whether the given number(11) is prime or not in the PHP programming language.

Program 1

<?php
//php code to check whether a number is prime or not
$num=11;
$count=0;
for($i=1; $i<=$num; $i++)
{
if(($num % $i)==0)
{
$count++;
}
}
if($count<3)
{
echo "$num is a prime number";
}//print if the number is prime
else{
echo "$num is not a prime number";
}//print if the number is not prime
?>

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

11 is a prime number

Check the prime number in PHP – #2

In this program, the user is asked to enter a number using a form in PHP. and the program checks whether the given number is prime or not in the PHP programming language.

Program 2

<form method="post">
Enter a number: <input type="text" name="input"><br>
<br>
<input type = "submit" name="submit" value="Check"/><br>
</form>
<?php
if($_POST)
{
  $input=$_POST['input'];
  for($i=2; $i<=$input-1; $i++){
    if($input%$i==0){
      $value=True;
    }
  }
  if(isset($value)&&($value)){
    echo 'The Number '.$input.' is not a prime';
  }else{
    echo 'The Number '.$input.' is a prime';
  }
  }
  ?>

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