We find ourselves adding, subtracting, and comparing things on a regular basis. These simple (or complex) operations are just as important in code. In C++, operators perform calculations and compute results. We rely on operators for tasks such as calculating areas and volumes of shapes, comparing values in an if/else statement and checking if a statement is true or false.
C++ likely would not exist without classes. As the original C programming language grew more decipherable, C++ was born. Because C++ was built entirely with objects in mind, C++ uses classes to make it easy to work with objects. Classes and objects became the building blocks C++ uses for creating streamlined and easy-to-read code.
What exactly is a C++ class, and how does it tie into making it easy to use, follow and compile code? We’re glad you asked.
Relational databases store information in tables — with columns that are analogous to elements in a data structure and rows that are one instance of that data structure. In SQL, a table cell without a value contains a special marker, NULL, which is not the same as zero, an empty string, or any other kind of value that works with equality tests; i.e.
NULL != 0,
NULL != "“, etc. The SQL Coalesce statement is one way of processing these NULL values for common uses like text processing.
Working within the world of HTML using CSS, site design is the ultimate goal. To reach that goal, you need to have an understanding of the way elements on a page are laid out. Quite simply, the CSS Box Model provides a guide to layout those elements.
The CSS Box Model is used to create a definition for the way the HTML elements are organized on the screen. This approach accounts for options such as margins, padding, borders, and all the properties that manipulate them.
Each element can be thought of as having its own box. As all the elements on a page have to work together with each other, it is quite important to know just how each of those boxes works. This brief tutorial will help explain the box model for beginners.
SQL (Structured Query Language) — pronounced “sequel” or “ess queue ell” — is a computer programming language tailored to interacting with data stored in relational databases. SQL provides all the necessary tools to create, read, update, and delete (CRUD) that data.
This SQL hub lists all the Udacity blog posts which cover SQL. Armed with this information you can craft “SQL queries” — tailored requests for information — from virtually any database (including MySQL, SQLite, Apache Presto, Firebird SQL, Google BigQuery, Oracle, Microsoft SQL Server, Sybase, SAP HANA, IBM DB2, and many others).