PHP Short Notes for DAVV MBA

File System:

Creating and Deleting a File:

• Use fopen() to create a new file.
• Use unlink() to delete a file from the server.

Reading and Writing Text Files:

• Use fread() to read data from a file.
• Use fwrite() to write data to a file.

Working with Directories in PHP:

• Use mkdir() to create a new directory.
• Use rmdir() to remove an empty directory.

Checking for Existence of File:

• Use file_exists() to check if a file exists.

Determining File Size:

• Use filesize() to get the size of a file in bytes.

Opening a File for Writing, Reading, or Appending:

• Use fopen() with different modes (w, r, a) for writing, reading, or appending.

Writing Data to the File:

• Use fwrite() to write content to an open file.

Reading Characters:

• Use fgetc() to read a character from a file.

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Forms:

• HTML forms collect user input on a web page.
• Users enter data in input fields, make selections, etc.
• Data submitted to a server for processing.

Super Global Variables:

• Predefined variables in PHP accessible globally.
• Examples: $_GET, $_POST, $_SESSION, $_COOKIE.
• Store and retrieve data across different parts of the script.

Super Global Array:

• Special array-like variables in PHP.
• Hold data from various sources, like form submissions.

Acquiring User Input:

• Collect user data using HTML forms.
• Forms use input fields, checkboxes, radio buttons, etc.

Importing User Input:

• PHP gets user input through form submissions.
• Access user input using $_POST or $_GET superglobals.

Accessing User Input:

• PHP processes user input by accessing superglobals.
• Example: $username = $_POST[‘username’];.

Combining HTML and PHP:

• Embed PHP code within HTML to make dynamic pages.
• Output PHP-generated data directly in HTML.

Using Hidden Fields:

• Hidden fields store data not shown to users.
• Useful for passing information between pages.

Redirecting Users:

• PHP can redirect users to different pages.
• Uses header() function to send HTTP headers.

File Upload and Scripts:

• HTML forms can upload files from user devices.
• PHP scripts handle uploaded files, process, and store.

Deleting a File:

• PHP script can delete files on the server.
• Uses unlink() function to remove files.

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FTP/SMTP Server:

• FTP transfers files, SMTP sends emails.
• FTP server handles file storage and transfer.
• SMTP server manages email sending and receiving.

Math Functions:

• Math functions perform calculations (add, subtract, etc.).
• Used in programming to manipulate numbers.

File Upload:

• Allows users to send files from their device to a server.
• Common in web applications for sharing data.

File Download:

• Enables users to get files from a server to their device.
• Used for accessing resources like documents or media.

E-Mail with PHP:

• PHP sends emails via SMTP protocol.
• Automates email creation and delivery.

PHP Configuration File:

• “php.ini” sets PHP runtime parameters.
• Controls behavior, memory usage, and more.

Error Tracking and Debugging:

• Process of finding and fixing code issues.
• Involves analyzing errors and testing code.

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Introduction to JavaScript:

• JavaScript is a scripting language for web development.
• Adds interactivity, dynamic behavior to websites.
• Runs on browsers, controls elements, and responds to user actions.

Form Validation using JavaScript:

• Validates user inputs in web forms before submission.
• Provides real-time feedback to users.
• Prevents incorrect or incomplete data from being submitted.
• Ensures data integrity and better user experience.

E-mail Validation using JavaScript:

• Validates email addresses entered in forms.
• Checks for proper format (username@domain).
• Ensures users provide valid email addresses.
• Helps reduce errors in email communication

jQuery:

• jQuery is a JavaScript library.
• Simplifies DOM manipulation and event handling.
• Shortens code for common tasks.
• Improves development speed and cross-browser compatibility.