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ex10.php
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<html>
<head>
<style>
div{
padding: 10px;
}
</style>
</head>
<body>
<div>
<h2>Prime Number Check</h2>
<form method="post" action="">
<label for="num">Enter a positive integer:</label>
<input type="number" name="num" id="num" min=0 required>
<input type="submit" value="Check">
</form>
</div>
</body>
</html>
<?php
function is_prime($number)
{
if ($number <= 1) {
echo " The number $number is not prime.";
return;
}
$divisors = 0;
for ($i = 1; $i <= $number; $i++) {
if ($number % $i == 0) {
$divisors++;
}
}
if ($divisors == 2) {
echo " The number $number is prime.";
} else {
echo " The number $number is not prime.";
}
}
// Method using square root for optimization
/*function is_prime($number)
{
if ($number <= 1) {
echo " The number $number is not prime.";
return;
}
for ($i = 2; $i <= sqrt($number); $i++) {
if ($number % $i == 0) {
echo " The number $number is not prime.";
return;
}
}
echo " The number $number is prime.";
}*/
// Another method
/*function is_prime($number)
{
if ($number <= 1) {
echo " The number $number is not prime.";
return;
}
for ($i = 2; $i <= $number / 2; $i++) {
if ($number % $i == 0) {
echo " The number $number is not prime.";
return;
}
}
echo " The number $number is prime.";
}*/
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$number = (int)$_POST["num"];
is_prime($number);
}
?>