PHP| Function to Check if a number is prime or not

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PHP| Function to Check if a number is prime or not

In this article, we will discuss the concept of the PHP| Function to 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, using a function and displaying the result on the screen in the PHP programming language.

Code to check prime number

Check the prime number using the PHP function- #1

In this program, the user defines a function with the parameter, and when the user calls the function with an argument, the program checks whether the given number is prime or not in the PHP programming language.

Program 1

<?php
//php code to check whether a number is prime or not 
//using function 
function checkPrime($num){
  //function definition
$n=0;
for($i=2; $i<($num/2+1); $i++){
  if($num%$i==0){
  $n++;
  break;
  }
}

if($n==0){
echo $num." is a prime number.";
//print if the number is a prime
}else{
echo $num." is not a prime number.";
//print if the number is not prime
}
}
checkPrime(20);
//Call the function with argument
?>

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

20 is not a prime number.

Check the prime number using the PHP function- #2

In this program, the user defines a function with the parameter, and when the user calls the function with an argument, the program checks whether the given number is prime or not in the PHP programming language.

Program 2

<?php
//php code to check whether a number is prime or not 
//using function 
function checkPrime($num){
  //function definition with parameter
for($i=2; $i<$num; $i++){
  if($num%$i==0){
  return 0;
  }
}
return 1;
}
$x=checkPrime(31);
//Call the function with argument
if($x==0){
echo "this is not a prime number.";
//print if the number is not prime
}else{
echo "this is a prime number.";
//print if the number is prime
}

?>

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