Php Developer

1. Parse error / Syntax Error: It is the type of error done by the programmer in the source code of the program. The syntax error is caught by the compiler. After fixing the syntax error the compiler compile the code and execute it. Parse errors can be caused dues to unclosed quotes, missing or Extra parentheses, Unclosed braces, Missing semicolon etc. 
2. Warning Errors : The main reason of warning errors are including a missing file. This means that the PHP function call the missing file.
3. Notice Error: It is similar to warning error. It means that the program contains something wrong but it allows the execution of script.
4. Fatal Error: It is the type of error where PHP compiler understand the PHP code but it recognizes an undeclared function. This means that function is called without the definition of function.

Every time you want to use a new class in your PHP project, first you need to include this class (using include or require language construct, that’s right this are not functions). However if you have __autoload function defined, inclusion will handle itself.
Example : 
This example attempts to load the classes MyClass1 and MyClass2 from the files MyClass1.php and MyClass2.php respectively.
spl_autoload_register(function ($class_name) {
include $class_name . '.php';
});

$obj = new MyClass1();
$obj2 = new MyClass2(); 
?>

1. Interface class supports multiple inheritance feature
Abstract class does not support multiple inheritances.
2. Interface does not contain a data member.
Abstract class does contain a data member.
3. The interface does not allow containers.
The abstract class supports containers.
4.An interface class only contains incomplete members which refer to the signature of the member.
Abstract class contains both incomplete(i.e. abstract) and complete members.
5. Since everything is assumed to be public, an interface class does not have access modifiers by default.
An abstract class can contain access modifiers within subs, functions, and properties.
6. Any member of an interface cannot be static.
Only a complete member of the abstract class can be static.

.htaccess is a configuration file of apache which is used to make changes in the configuration on a directory basis. Htaccess file is used to do changes in functions and features of the apache server. Htaccess is used to rewrite the URL. It is used to make site address protected. Also to restrict IP addresses so on particular IP address site will not be opened.

Singleton is a creational design pattern that ensured that a class has only one instance, while providing a global access point to this instance.

Tip 1: Write comments and documentation
Tip 2: Use helper methods
Tip 3: Write readable yet efficient code