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PHP function Exercises: Check whether a number is prime or not

PHP function: Exercise-2 with Solution

Write a function to check whether a number is prime or not.

Note: A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.

Pictorial Presentation:

PHP function Exercises: Check whether a number is prime or not

Sample Solution:

PHP Code:

<?php
function IsPrime($n)
{
 for($x=2; $x<$n; $x++)
   {
      if($n %$x ==0)
	      {
		   return 0;
		  }
    }
  return 1;
   }
$a = IsPrime(3);
if ($a==0)
echo 'This is not a Prime Number.....'."\n";
else
echo 'This is a Prime Number..'."\n";
?>

Sample Output:

This is a Prime Number..

Flowchart :

Flowchart: Check whether a number is prime or not

PHP Code Editor:

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Previous: Write a function to calculate the factorial of a number (a non-negative integer). The function accepts the number as an argument.
Next: Write a function to reverse a string.

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PHP: Tips of the Day

PHP: Anonymous recursive PHP functions

In order for it to work, you need to pass $factorial as a reference

$factorial = function( $n ) use ( &$factorial ) {
    if( $n == 1 ) return 1;
    return $factorial( $n - 1 ) * $n;
};
print $factorial( 5 );

Ref : https://bit.ly/38dj7jm