Private data in objects is a trickier proposition in JavaScript than in most languages. Only the most recent spec (ES12) specifically addresses private data, so the way to hide it has until recently been to put it in a closure. … Continued
Garbage collection is a process of automatically releasing memory when it is no longer in use. In lower-level languages such as C, it is often necessary to allocate and deallocate memory manually. When creating a dynamically resizable array, for example. … Continued
Procs Yielding to blocks from methods is the simplest way to access closures. However, yield is a bit limited, because it can only invoke the block directly. It can’t send the block somewhere else to be invoked. To do that, … Continued
Scope An entity’s scope is the area of the application in which it is “visible.” For example, a variable’s scope is the area of an application that can access the variable. And an object’s scope is the area of an … Continued
Methods With an Explicit Block Parameter A method that uses an explicit block parameter has these rules: Only one block parameter is allowed. It must be last parameter in the list. Its name must begin with &. The & tells … Continued
What are Blocks? Blocks in Ruby are chunks of code that are — almost — nothing but chunks of code. A block is not a method. It is not a proc or a lambda. And, despite the popular statement that … Continued
Hoisting in JavaScript is often misunderstood to mean that certain bits of code get moved to the top of the page before they are executed. This is not so; what actually happens is that code does not always run in … Continued
An entity is some sort of “thing” that a database keeps track of. Entities that are some part of the domain being modeled are called kernel entities or independent entities. There are other entities called associative entities that help relate … Continued
One-to-one relationships are the result of splitting one entity into two parts. This article covers some reasons to do that. (This article also assumes familiarity with terms such as entity, cardinality, modality and attributes. If you’re not familiar with these, … Continued
Structured Query Language, or SQL, is the standard language for interacting with data stored in Relational Database Management Systems (RDBMSs). Microsoft SQL Server, Oracle, IBM DB2, MySQL and PostgreSQL are a few popular RDBMSs that use SQL. Each SQL-based RDBMS … Continued