This article discusses about how to write a website scraper using PHP for web site data extraction. The concepts taught can be applied and programmed in Java, C#, etc. Basically any language that has a powerful string processing capability. This article will teach you the basics of website scraping. The article will further cover a tutorial to find web ranking from Yahoo.com search engine.
I have developed these based on my freelancing experience. Though I have discontinued freelancing, but would like to share my practices with you. These are basic practices and have been developed over time with experience (good and bad). Please feel free to leave your experiences and comment on this article.
In this tutorial we will cover the following:
- What is an exception?
- The use of a try…catch block
- Anatomy of PHP5 Exception class
- Extending the Exception class
- A note on unhanded exceptions
In this PHP tutorial we will understand the following:
- Meaning of Final Class
- Meaning of Final Method
- When to declare a class as final
- When to declare a method as final
In this tutorial you will learn all about static data members and methods
- Meaning of static data members
- Meaning of static methods
- Defining static data members in PHP5
- Defining static methods in PHP5
- Accessing static data members in PHP5
- Accessing static methods in PHP5
- Rules to keep in mind for static methods
In this tutorial we will learn the following:
- Meaning of Polymorphism
- Why method polymorphism cannot be achieved in PHP
- PHP 5 Object Polymorphism
In this post, we learn what is an abstract class and an interface.
- What is an Abstract Class?
- Private methods cannot be Abstract
- What is an Interface?
- Defining an Interface
- Abstract Class v/s Interface
Here is a script that will allow you to print a nested array upto any level. Can I request you to please review this and let me know how this can be further optimized.
In the tutorial we will understand what is Inheritance in general and how to inherit classes in PHP5.
Definition of Inheritance:
Inheritance is the mechanism of deriving a new class from an existing class. It allows a sub-class / child class to share/inherit the attributes and behaviors of a base-class or parent class. These inherited attributes and behaviors are usually modified by means of extension.
In PHP4 the only constants that we would declare were global constants. In PHP5 it is possible to define a class level constant. These constants are specific to the class and hence don’t clutter the global level constant space.