Interview Questions

CONSTRUCTOR : PHP allows developers to declare constructor methods for classes. Classes which have a constructor method call this method on each newly-created object, so it is suitable for any initialization that the object may need before it is used.

DESTRUCTORS : PHP 5 introduces a destructor concept similar to that of other object-oriented languages, such as C++. The destructor method will be called as soon as all references to a particular object are removed or when the object is explicitly destroyed or in any order in shutdown sequence.

UNION selects only distinct values whereas UNION ALL selects all values and not just distinct ones

An SQL statement is a string of characters that conforms to the syntax and format specified in the international standard.

A query is a statement that returns a record-set.

1)Divide by zero        – This is raised when any number is attempted to divide by zero.

2)TOO MANY ROWS   - A SELECT INTO statement returns more than one row.

3)CASE_NOT_FOUND - No choice in the WHEN clause of a case statement is selected.

4)LOGIN_DENIED      - An attempt to login with an invalid username or password.

5)PROGRAM_ERROR  - An internal PL/SQL problem.

When an object is passed by value, this means that a copy of the object is passed. Thus, even if changes are made to that object, it doesn’t affect the original value. 

When an object is passed by reference, this means that the actual object is not passed, rather a reference of the object is passed. Thus, any changes made by the external method, are also reflected in all places.

It is necessary to understand some of the concepts used extensively in object oriented programming.These include

Objects
Classes
Data abstraction and encapsulation
Inheritance
Polymorphism
Dynamic Binding
Message passing

Change management is the biggest challenge in each and every industry. After requirements stage when development is started client will come-up with some new changes or enhancements. 

Cross departmental or cross team management – like conflict management between teams. Also individuals. This requires soft skills and smartness. 

Communication problems – In real time this can happen. You might be good in speaking and understanding the English language. BUT sometimes it happens like Different people across the globe speak different style of English. In USA itself Mexico people speak English differently. Romans speak different English. So at initial level to understand the accent can be a challenge but after some time you will become perfect. 

- Inheritence permits code reusability. 

- Reusability saves time in program development. 

- It encourages the reuse of proven and debugged high-quality software which reduces the problems after a system becomes functional.