empty() function
$str = '';
if (empty($str)) {
echo "The string is empty";
} else {
echo "The string is not empty";
}
Direct comparison
$str = '';
if ($str === '') {
echo "The string is empty";
} else {
echo "The string is not empty";
}
array_key_exists() function
$array = array(
"key1" => "value1",
"key2" => "value2",
"key3" => "value3"
);
$keyToCheck = "key2";
if (array_key_exists($keyToCheck, $array)) {
echo "The key '$keyToCheck' exists in the array.";
} else {
echo "The key '$keyToCheck' does not exist in the array.";
}
empty() function
$arr = array();
if (empty($arr)) {
echo "The array is empty";
} else {
echo "The array is not empty";
}
count() function
$arr = array();
if (count($arr) == 0) {
echo "The array is empty";
} else {
echo "The array is not empty";
}
sizeof() function
$arr = array();
if (sizeof($arr) == 0) {
echo "The array is empty";
} else {
echo "The array is not empty";
}
margins
<!DOCTYPE html>
<html>
<head>
<title>Spacing Example</title>
<style>
.spacer {
margin-bottom: 20px;
}
</style>
</head>
<body>
<div class="spacer"></div>
<p>This is a paragraph with some space below it.</p>
</body>
</html>
padding
<!DOCTYPE html>
<html>
<head>
<title>Spacing Example</title>
<style>
p {
padding-bottom: 20px;
}
</style>
</head>
<body>
<p>This is a paragraph with some space below it.</p>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
<link rel="icon" href="favicon.ico" type="image/x-icon">
</head>
<body>
<!-- Your HTML content here -->
</body>
</html>
<style>
<!DOCTYPE html>
<html>
<head>
<title>CSS Example</title>
<style>
body {
background-color: #f0f0f0;
font-family: Arial, sans-serif;
}
h1 {
color: blue;
}
p {
font-size: 16px;
}
</style>
</head>
<body>
<!-- Your HTML content here -->
</body>
</html>
external CSS file
<!DOCTYPE html>
<html>
<head>
<title>CSS Example</title>
<link rel="stylesheet" type="text/css" href="styles.css">
</head>
<body>
<!-- Your HTML content here -->
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>Link Example</title>
</head>
<body>
<a href="https://www.example.com">Visit Example.com</a>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>Video Example</title>
</head>
<body>
<video width="640" height="360" controls>
<source src="path_to_your_video.mp4" type="video/mp4">
Your browser does not support the video tag.
</video>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>Background Image Example</title>
<style>
body {
background-image: url("path_to_your_image.jpg");
background-size: cover;
}
</style>
</head>
<body>
<!-- Your content here -->
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>Image Example</title>
</head>
<body>
<img src="path_to_your_image.jpg" alt="Description of the image">
</body>
</html>