Find prime numbers between the range

  1. <?php
  2.  
  3. $start=0;
  4. $end=100;
  5. $prime_numbers=array();
  6. for($i=$start;$i<=$end;$i++){
  7. 	if(is_prime($i)==true){
  8. 		$prime_numbers[]=$i;
  9. 	}
  10. }
  11.  
  12. var_dump($prime_numbers);
  13. function is_prime($num){
  14. 	$no=$num;
  15. 	$prime=true;
  16. 	for($i=2;$i<=($no/2);$i++)
  17. 	{
  18. 		if($no%$i==0){
  19. 			$prime=false;
  20. 			break;
  21. 		}
  22. 	}
  23. 	return $prime;
  24. }
  25.  
  26. ?>

 

 

 

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prime no or not

First of all, I want to tell you that what is the prime no.

Prime no is the no which can’t be divided by other than 1 and itself.

Prime No? Yes : No;

  1. <?php
  2. $no=8;
  3. $prime=true;
  4. for($i=2;$i<($no/2);$i++)
  5. {
  6.     if($no%$i==0){
  7.         $prime=false;
  8.         break;
  9.     }
  10. }
  11. if($prime==true){
  12.     echo "<br/>Number is Prime<br/>";
  13. }
  14. else{
  15.     echo "<br/>Number is not prime<br/>";
  16. }
  17. ?>

 

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