Objects and Hash tables in JavaScript

Hash tables share many similarities with objects, like storing data in key-value pairs and having the same syntax to add and retrieve elements. We can think of hash tables as a dictionary where you can look up a word definition using just the letter/letters, except for hashing the key string into a series of numbers that will be used to access the value in the array that holds the values.

So in general, we should use hash tables instead of objects because they provide a very fast access to the data stored within.

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Big O Notation

Big O Notation is a mathematical expression that describes how much time an algorithm takes to run according to the size of it's inputs; mostly concerned about the worst case scenario. Types: 1- Constant Time O(1): On this order, regardless of the number of items, the iterations(time) are constant. Example: const getFirstItem = items => items[0]; getFirstITem([1, 2, 3, 4]); // 1 (one iteration) getFirstItem(['b', 'd', 'g']); // 'b' (one iteration) 2- Linear Time O(n): On this order, the worst case grows with the number of items. Example: Javascript's built in function indexOf, it loops over an array to find the correct index of the passed element. The worst case is looping over the whole array. [1, 2, 4, 9, 23, 12].indexOf(12); 3- Quadratic Time O(n ^ 2): For this order, the worst case time is the square of the number of inputs. It grows exponentially according to the number of inputs. Example: Using nested loo...

Deployment In Simple Words

Deployment is the hardest part in the lives of computer coders, it's harder than making apps and games. Any game that you have ever used for example on your computer had to go through many operations to be in the final form it is when you first bought it. The last operation is deployment as you might have guessed. It's about getting your video game ready to use and play on any computer out there. Many issues could happen while deploying the game since we have many environments to deal with these days.

Relational Databases

Relational databases are, well... a collection of data items that have relations between them. These relations are made by associating a one table's primary key with another table's foreign key. It is a great advancement from the old long table that was used to store data which was inefficient in terms of search, memory and space. And as for normalization; it means a process in which tables are structured to eliminate redundancy and repetition among data and the CRUD operations side-effects. And as a direct result we improve the performance of our queries. An example of a relational database would be two tables; one for student and the other for school. Both of these tables have a column for the school id, and so we make a connection between by assigning the first one as a primary key and the other as foreign key.

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