<!DOCTYPE html>
<html>
<head>
<title>PHP Calculator</title>
</head>
<body>
<h2>Simple PHP Calculator</h2>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>">
<label for="num1">Number 1:</label>
<input type="text" id="num1" name="num1" required><br><br>
<label for="num2">Number 2:</label>
<input type="text" id="num2" name="num2" required><br><br>
<label for="operator">Choose an operator:</label>
<select id="operator" name="operator">
<option value="+">Addition (+)</option>
<option value="-">Subtraction (-)</option>
<option value="*">Multiplication (*)</option>
<option value="/">Division (/)</option>
</select><br><br>
<input type="submit" value="Calculate">
</form>
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$num1 = $_POST["num1"];
$num2 = $_POST["num2"];
$operator = $_POST["operator"];
switch ($operator) {
case "+":
$result = $num1 + $num2;
break;
case "-":
$result = $num1 - $num2;
break;
case "*":
$result = $num1 * $num2;
break;
case "/":
if ($num2 != 0) {
$result = $num1 / $num2;
} else {
$result = "Cannot divide by zero!";
}
break;
default:
$result = "Invalid operator!";
}
echo "<h3>Result: $result</h3>";
}
?>
</body>
</html>
Category: PHP
Free PHP Code Examples
Write to a file
fwrite() function
<?php
$filename = "example.txt";
$file = fopen($filename, "w") or die("Unable to open file!");
$text = "Hello, World!";
fwrite($file, $text);
fclose($file);
echo "Data written to $filename successfully.";
?>
Check if file has been modified
filemtime() function
<?php
$file_path = 'example.txt';
$file_modified_time = filemtime($file_path);
$current_time = time();
if ($file_modified_time > $current_time - 3600) {
echo "The file has been modified within the last hour.";
} else {
echo "The file has not been modified within the last hour.";
}
?>
Check if file is utf8
<?php
$file_path = 'example.txt';
$file_content = file_get_contents($file_path, NULL, NULL, 0, 1000);
$encoding = mb_detect_encoding($file_content, 'UTF-8', true);
if ($encoding === 'UTF-8') {
echo "The file is encoded in UTF-8.";
} else {
echo "The file is not encoded in UTF-8.";
}
?>
Check if file is writable
is_writable() function
<?php
$file_path = 'example.txt';
if (is_writable($file_path)) {
echo "The file is writable.";
} else {
echo "The file is not writable.";
}
?>
Check if file is readable
is_readable() function
<?php
$file_path = 'example.txt';
if (is_readable($file_path)) {
echo "The file is readable.";
} else {
echo "The file is not readable.";
}
?>
Check if file is pdf
finfo_file() function
<?php
$file_path = 'example.pdf';
$file_info = finfo_open(FILEINFO_MIME_TYPE);
$mime_type = finfo_file($file_info, $file_path);
finfo_close($file_info);
if ($mime_type === 'application/pdf') {
echo "The file is a PDF.";
} else {
echo "The file is not a PDF.";
}
?>
Check if file is image
<?php
$file_path = 'example.jpg';
$image_info = getimagesize($file_path);
if ($image_info !== false) {
if (strpos($image_info['mime'], 'image/') === 0) {
echo "The file is an image.";
} else {
echo "The file is not an image.";
}
} else {
echo "The file is not accessible or is not an image.";
}
?>
Check path of file
realpath() function
<?php
$file_path = 'example.txt';
$real_path = realpath($file_path);
if ($real_path !== false) {
echo "The real path of the file is: $real_path";
} else {
echo "The file path does not exist or is not accessible.";
}
?>
Check file size
filesize() function
<?php
$filename = 'example.txt';
$filesize = filesize($filename);
if ($filesize !== false) {
echo "The size of the file is: $filesize bytes";
} else {
echo "Failed to get the file size.";
}
?>