Monthly Archives: September 2014

Implement a Singleton Pattern in Javascript

http://stackoverflow.com/questions/1479319/simplest-cleanest-way-to-implement-singleton-in-javascript var SingletonClass = (function(){ function SingletonClass() { //do stuff } var instance; return { getInstance: function(){ if (instance == null) { instance = new SingletonClass(); // Hide the constructor so the returned objected can’t be new’d… instance.constructor = null; … Continue reading

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Overloading in PHP

Overloading has a different meaning in PHP. PHP does not support function overloading in the same manner as C++. However it possible to pass different number of arguments to a function using func_get_args. function findSum() { $sum = 0; foreach … Continue reading

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Traits

As of PHP 5.4.0, PHP implements a method of code reuse called Traits. Traits are a mechanism for code reuse in single inheritance languages such as PHP. A Trait is intended to reduce some limitations of single inheritance by enabling … Continue reading

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Index in MySQL

Most MySQL indexes (PRIMARY KEY, UNIQUE, INDEX, and FULLTEXT) are stored in B-trees. Exceptions are that indexes on spatial data types use R-trees, and that MEMORY tables also support hash indexes. http://www.kylescousin.com/2010/09/a-simple-explanation-on-how-b-tree-database-indexes-work/

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How does MySQL uses indexes ?

If the table has a multiple-column index, any leftmost prefix of the index can be used by the optimizer to find rows. For example, if you have a three-column index on (col1, col2, col3), you have indexed search capabilities on … Continue reading

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Language Comparision

Variables JS var colors = “green”; PHP $colors = “green”; ========================================== Array JS var colors ; colors = [‘white’,’black’,’brown’]; colors[0]; OR var colors = Array(‘white’,’black’,’brown’); colors.item(0); ========================================== Object JS: var hotel = { name: ‘Super8’, rooms: 40, booked: 25 checkAvailability … Continue reading

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