Interview Questions

Notices, Warnings and Fatal errors are the types of errors in PHP

Notices: 

Notices represents non-critical errors, i.e. accessing a variable that has not yet been defined. By default, such errors are not displayed to the user at all but whenever required, you can change this default behavior.

Warnings: 

Warnings are more serious errors but they do not result in script termination. i.e calling include() a file which does not exist. By default, these errors are displayed to the user.

Fatal errors: 

Fatal errors are critical errors i.e. calling a non-existent function or class. These errors cause the immediate termination of the script.

SELECT * FROM table_name ORDER BY column_name desc Fetch first 5 rows only;

A cookie is a small text file on the client machine either in the client’s file system or memory of client browser session.

The XML DOM (document object model) is used the access and management of xml. It is a platform that is language neutral and allows a program or a script to dynamically access a document. It also allows the updation of content as well as the structure and style of the document. It is responsible for the defining of the object and properties of all xml elements as well as to define the methods for their access. There are various methods that can be used in xml dom such as:

- getElementsByTagName: used to call a specific user defined tag.

- setAttribute: used to change the value of an existing attribute.

- appendChild: used to add a child node to another node.

Both these are used to combine the results of different SELECT statements.

    UNION       - Selects only distinct values 

    UNION ALL - Selects duplicate values also

Syntax:

    SELECT column_name(s) FROM table1

    UNION / UNION ALL

    SELECT column_name(s) FROM table2;

Notice that each SELECT statement within the UNION must have the same number of columns. The columns must also have similar data types. Also, the columns in each SELECT statement must be in the same order.

A prompt box allows the user to enter input by providing a text box.

Secondary market refers to market where securities are traded after being initially offered to the public in the primary market and/or listed on the stock exchange.