When developing a web application with PHP, we frequently need to print or echo a few HTML results. This work can be accomplished in a variety of ways. Here are a few examples of methods:
Using “echo or print”:– HTML markup, javascript, text, and variables may all be shown with PHP echo or print.
Example 1: This example uses PHP echo to display the result.
Output:-
Example 2: This example uses PHP print to display the result.
Output :
Using echo shorthand or separating HTML: Any expression, variable value, or HTML markup can be shown with the PHP echo shortcut.
Example 1: This example uses PHP echo shorthand to display the result.
The client-side programming language is JavaScript, while the server-side scripting language is PHP. Client-side JavaScript is used to examine and verify client information, whereas server-side PHP is used to communicate with the database. HTML is used in PHP as a string in the code. We generate JavaScript code as a string in the PHP code to present it to the browser.
Example 1: Write JavaScript code in PHP code
Example 2: Write JavaScript code outside of PHP code (in same PHP file)
Example 3: JavaScript Function – DOM Manipulation (in same PHP file)
I’ll teach you how to use PHP code in your HTML pages in this post. It’s for PHP newbies who want to improve their command of the world’s most popular server-side programming language.
PHP is a programming language that runs on the server. That is, a PHP script is run on the server, the output is created on the server, and the result is delivered to the client browser as HTML to render. It’s natural to integrate PHP and HTML in a script, but as a newbie, it might be difficult to figure out how to do so.
Ways to Combine PHP and HTML
When it comes to using PHP with HTML, there are two ways to take. The first is to embed the PHP code in the.html extension of your HTML file—this necessitates some particular considerations, which we’ll go over shortly. The alternative approach, and the recommended method, is to use .php files to mix PHP and HTML elements.
PHP is a server-side scripting language, which means that the code is interpreted and executed on the server. If you put the following code in your index.html file, for example, it won’t work right away.
First and foremost, don’t worry if you’ve never seen combined PHP and HTML code before; we’ll go over it in depth later in this post. In your browser, the following is displayed as a result of the preceding example:
<?php echo "Hello World" ?>
As you can see, PHP tags in your.html page are not identified by default, and they are displayed as plain text without processing. Because the server is generally set up to only run PHP for files with the .php suffix, this is the case.
You may instruct the server to run your.html files as PHP files if you wish to run your HTML files as PHP, but it’s much preferable to place your mixed PHP and HTML code inside a .php file.
How to Add PHP Tags in Your HTML Page
When integrating PHP code with HTML text, you must use the PHP start tag <?php and the PHP end tag?> to encapsulate the PHP code. The PHP code enclosed between these two tags will be performed on the server before the requested file is given to the client browser.
Let’s have a look at a very simple example that uses PHP code to show a message. Create an index.php file in your document root with the following contents.
Output:-
As you can see, PHP code is parsed and performed on the server before being combined with HTML and delivered to the client browser.
Consider the following scenario:
This will display the current date and time, allowing you to create dynamic output from the server by inserting PHP code between the HTML tags. It’s crucial to note that any code between <?php and ?> the tags will be treated as PHP and the output will be interspersed with HTML tags once the page is performed on the server.
How to Use PHP Loops in Your HTML Page
One of the most typical jobs you’ll encounter while creating PHP scripts is iterating through arrays to generate HTML output. We’ll look at how to iterate through an array of objects and create output in this section.
In most situations, you’ll need to show material from an array that you’ve filled from a database or another source. For the sake of clarity, we’ll initialize the array with various values at the start of the script in this example.
To begin, we’ve set up the array at the start of our script. The foreach technique was then used to loop over the array values. Finally, the array element value was shown using the echo construct.
Output:-
The same example with a while loop looks like this:
And the result will be identical. So that’s how foreach and while loops may be used to produce HTML content from PHP arrays.
How to Use PHP Short Tags
We’ve used the <?php beginning tag as a starting tag in all of the examples thus far. In reality, PHP has a variant,<?=, that you may use as a short-hand syntax to show a text or the value of a variable.
By using the shorthand syntax, we may display a value without using the echo or print construct. When using echo or print to display something, the shorthand syntax is quick and easy to understand.
Including Code from Different Files
There are many instances where the same code must be used on many pages of a website. The header and footer sections of a webpage are an illustration of this. The HTML in these sections is usually the same as it is throughout the website.
Consider it as putting a website’s common CSS rules into a stylesheet rather than into the style tags on each pages.
In PHP, there are four functions that may be used to include additional files within a PHP file. include(), include once(), require(), and require once() are the four functions ().
The include() function will include and evaluate the provided file, and if it cannot find the file, it will issue a warning. The need() method accomplishes the same thing, but instead of a warning, it returns an error if the file isn’t found.
You may accidentally include the same file several times while working on large projects. This might result in issues such as function redefinition. Using PHP’s include once() and require once() methods is one approach to prevent these problems.
To demonstrate how to use these functions, we’ll use code from a prior section. In this example, I’ll use include(). Make a file named header.php and paste the code below into it.
Output:-
Create another file called date.php and place the following code in it.
Create one more file called day.php and place the following code in it.
In core PHP we learn only the basic elements but in advanced PHP we are learning many other elements or their uses in real-life projects that is why it is called advanced PHP. Remember that there is no difference between core PHP and advanced PHP.
why we should learn advanced php?
The good feature of PHP is that it is very robust and scalable. PHP is much the same as if it was an object-oriented language, making it a very easy language to deal with. PHP also has a very strong meta-language for programmers. PHP has increased demand for language development year over year.
Class & Object
Class:-
PHP class is a group of values and a set of operations to manipulate the value or to change the value.
Classes are the blueprints of objects.
Classes are nothing without objects.
Class is a programmer-defined data type.
The syntax for defining a class in PHP is very simple.
We use the keyword class followed by the name of the class.
Rules for creating class:-
Class name can be any valid label like(Vikash,Ram,Boss,Cat,Plant e.t.c).
Cannot be used Php reserved words.
The class name, should start with letter or underscore.
for remembering class, the class name starts with the first capital letter.
syntax:-
class Classname
{
var&variable_name;
var&variable_name;
var&variable_name;
function Method_name()
{
body of method;
}
function Method_name()
{
body of method;
}
function Method_name(parameter_list)
{
body of method;
}
}
Object:-
Objects are defined from classes.
An object of a class a copy of each variable defined in the class is created.
file_get_contents( ) Function is used to read entire file into a string. This function is the preferred way to read the contents of a file into a string. Because it will use memory mapping techniques, if this is supported by the server, to enhance performance. This function is binary-safe (meaning that both binary data, like images, and character data can be written with this function). The function returns the read data or FALSE on failure.
What is file_get_contents() Function?
The file_get_contents( ) function in PHP is a built-in function for reading a file and converting it to a string. The function makes advantage of server-supported memory mapping methods, which improves speed and makes it a favored method of reading file data.
Closing file in php is all related to fclose( ) Function. With the help of this code we can run closing function in php.
What is fclose( ) Function in php?
In PHP, the fclose() method is used to close a file referenced by an open file pointer. If the method fclose() is successful, it returns true; otherwise, it returns false. It accepts the file that needs to be closed as an input and closes it.
Syntax:
bool fclose( $file )
Parameters:
The $file argument is the only one accepted by PHP’s fclose() function. The file that has to be closed is specified by this argument.
Return Value:
If it succeeds, it returns true; if it fails, it returns false.
Errors And Exception:
If you want to read the contents of a file that was written using the fwrite() function, you must first shut it with the fclose() function.
For remote files, PHP’s fclose() method does not work. It only works with files that the server’s filesystem can access.
The feof() function in PHP is an inherent function that checks a file pointer for the end-of-file. It determines whether or not the “end-of-file” has been reached. If the size of the content of a file is not known ahead of time, the feof() method is used to loop over it.
Why feof () used in Reading file ?
If the end-of-file has been reached or an error has occurred, the feof() method returns True. Otherwise, False is returned.
Syntax:
feof( $file )
Parameters:
In PHP, the feof() method takes only one parameter, $file. The file to be examined for end-of-file is specified by this argument.
Return Value:
If the end of the file has been reached or an error has occurred, it returns TRUE. Otherwise, False is returned.
Errors And Exception:
If the supplied file reference is invalid, it enters an infinite loop since end-of-file does not return True.
If a connection opened by fsockopen() is not terminated by the server, the feof() function hangs.
Let’s take one Example:-
Below examples will explain the feof() function:
Example 1:- In the below program the file named “test.txt” contains only a single line of text which is “This file consists of only a single line.”.
Output:
Example 2:- In the below program the file named “test-test.txt” contains the following text.
This is the first line.
This is the second line.
This is the third line.
This function is used to read a single line from a file. You can pass this function a file handle corresponding to an open file, and optional length.
Why fgets() used in Reading file?
It returns a line from a file pointer and terminates at a given length, end of file(EOF), or new line, whichever comes first.
The fgets() function is passed the file to read and the number of bytes to read as arguments, and it returns a string of length -1 bytes from the file indicated by the user.
If it fails, it returns False.
Syntax:-
fgets(file, length)
Parameters Used:
The fgets() function in PHP accepts two parameters.
file : It specifies the file from which characters have to be extracted.
length : It specifies the number of bytes to be read by the fgets() function. The default value is 1024 bytes.
Return Value : It returns a string of length -1 bytes from the user-specified file, or False if the operation fails.
Errors And Exceptions:-
Because it reads a single line at a time, the method isn’t designed for huge files, and reading a long file can take a long time.
If the fgets() method is called more than once, the buffer must be emptied.
Although the fgets() method returns the Boolean False, it frequently produces a non-Boolean result that evaluates to False.
Let’s take one Example:-
Suppose there is a file named “test.txt” which consists of :
This is the first line.
This is the second line.
This is the third line.
PHP has a number of functions for reading data from files. You may read entire file data, read data line by line, or read data character by character using various methods.
How many types of PHP file Read Functions are:-
The available PHP file read functions are given below.
fread()
fgets()
feof()
PHP readfile() Function
Reads a file and publishes it to the output buffer with the readfile() method.
Assume we have a text file on the server named “webdictionary.txt” that looks like this:
AJAX = Asynchronous JavaScript and XML
CSS = Cascading Style Sheets
HTML = Hyper Text Markup Language
PHP = PHP Hypertext Preprocessor
SQL = Structured Query Language
SVG = Scalable Vector Graphics
XML = EXtensible Markup Language
The following is the PHP code for reading the file and writing it to the output buffer (the readfile() method returns the number of bytes read if successful):
Example:-
If all you want to do is open a file and read its contents, the readfile() method comes in handy.
