The isset() function is used to check if a variable is set or not. It returns true if the variable is set and false if the variable is not set.
Example:
$name = “John”;
if(isset($name)) {
echo “Name is set”;
} else {
echo “Name is not set”;
}
// Output: Name is set
GET Method
The GET method is used to retrieve information from a server. It is the most commonly used method, and is used when a user clicks a link, submits a form, or enters a URL into their browser.
Example: When a user enters the URL of a website into their browser, the browser sends a GET request to the server hosting the website.
POST Method
The POST method is used to send data to a server. It is typically used when a user submits a form on a website.
Example: When a user submits a form on a website, the browser sends a POST request to the server hosting the website. The data from the form is sent along with the POST request.
Echo and Print are both language constructs used to output data to the screen.
The difference between echo and print is that echo has no return value while print has a return value of 1 which can be used in expressions.
Example:
echo “Hello World”;
print “Hello World”;
The most recent version of PHP is version 7.4.7, released on April 28, 2020.
Example:
Include and Require are both used to include a file into a php script. The main difference between them is that when a file is included with the include statement and PHP cannot find it, the script will continue to execute:
Example:
However, when a file is included with the require statement and PHP cannot find it, the script will stop executing:
Example:
PHP (Hypertext Preprocessor) is a server-side scripting language used to develop dynamic web applications. It is a powerful language that can be embedded into HTML.
Example:
The above code will output “Hello, John”.
1. Inline CSS: This is the simplest way to apply CSS to a web page. With inline CSS, you apply the style directly to the HTML element using the style attribute and CSS declarations. For example:
2. Internal or Embedded CSS: Internal CSS is used when you want to apply a unique style to a single HTML page. You can define internal CSS in the section of an HTML page, by using the tag. For example:
h1 {
color: blue;
font-size: 24px;
}
3. External CSS: External CSS is used when you want to apply the same style to multiple HTML pages. You can link to an external CSS file using the tag. For example:
Resetting a CSS is a process of removing all the default styling of HTML elements and setting them to a common baseline. This ensures that all elements are styled consistently across different browsers. For example, if you reset the CSS, all
Normalizing a CSS is a process of preserving useful default styles while also correcting cross-browser inconsistencies. It is a more modern approach than resetting a CSS, as it allows for more flexibility in styling elements. For example, if you normalize the CSS,
Comments in CSS are added with the /* */ syntax.
/* This is an example of a CSS comment */
body {
background-color: #e6e6e6;
}
ID: An ID is an attribute that is used to uniquely identify an element on a web page. An ID can be used to identify one element, or multiple elements if the same ID is used for each element.
Example:
This is the introduction paragraph.
Class: A class is an attribute that is used to group elements on a web page. A class can be used to identify one element, or multiple elements if the same class is used for each element.
Example:
This is the introduction paragraph.
Vaibhav Kothia