Java Script Objects

JavaScript objects are also datatypes. Just like int, string but the difference here is objects can contain properties and variables both. Properties can be of JSON data type or in the form of key-value pairs. Objects are stored in the heap memory compared to other data types which are stored in stack memory

Comments

Magic Function in PHP (sleep() and wakeup() )

There are many magic methods in PHP like __construct(), __destruct(), __callback(), __get(), __set(), __sleep(), __wake() and many more. But we will be takingon on __sleep() and __wake(). __sleep() : serialize() checks if your class has a function with the magic name __sleep(). If so, that function is executed prior to any serialization. It can clean up the object and is supposed to return an array with the names of all variables of that object that should be serialized. If the method doesn't return anything then NULL is serialized and E_NOTICE is issued. serialize() is used for the representation of the storage class for storing the value. Serializing an object means converting it to a byte stream representation that can be stored in a file. The use of __sleep() to commit the pending task. If a bulk data is being inserted then at that time __sleep can be used. it will not release the object unless the work is not completed....

What are the effects of indexing on database tables?

The working of Index in database tables is the same as index work in a Text Book . It will help to browse the desired content faster in a book. we use to see the index on the first page then we check the page where it is in the book and then we directly come to that page, instead of going through all pages. Now databases , same happen with tables, if you are applying select query on the table, it will also check for the index and then return you the required field. It will return the field faster on which index is applied. Or in language, we can say that the index one query will execute faster instead of the non-indexed one. Join will execute faster on indexed one. eg- Consider a Table Product with `id` as Primary Key id name price category_id location_id Table Info- Now Applying Index on category_id SELECT category_id FROM product WHERE category_id='5'; SELECT ca...

What Make Facebook page load faster ?

Facebook has a “ Lazy Loading ” system they call “ BigPipe ” that helps the pages load fast. Facebook breaks each page down into sections they call “ Pagelets” , and using Javascript only load the most important Pagelets first then load the less important ones shortly afterward. And pipeline them through several execution stages inside web servers and browsers, as the modern microprocessor do to serve the various request in an order to increase the productivity. Big Pipe is totally implemented in PHP and javascript. By loading and rendering the main page structure first with minimal info on it, the page appears to load quicker than having to wait for a complete page to download and then render. To exploit the parallelism between web server and browser, BigPipe first breaks web pages into multiple chunks called pagelets. Just as a pipelining microprocessor divides an instruction’s life cycle into multiple stages (such as “instruction fetch”, “instruction decode”, ...

Geek Answer

Search This Blog