terminology

There are HTML tags, such as <img /> , <input /> and <button /> , that need no ending tag ( </img> , </input> and </button> ). What is the term that describes this type of tags? This syntax has a variety of names depending on what language you are using. The best way to find out what it is called is to look at the specification for the specific language. HTML 4.x I can't find any mention of this syntax in the HTML 4.x specification. It is not valid syntax. HTML 5 In the HTML 5 specification the / character (called a SOLIDUS) is valid but has no effect for void elements such as <br /> , <hr />

So I know what pragma is, and what it's used for, but what is the meaning of the word itself? I've used it many times in code, but I never really knew what the word actually means or stands for. martin clayton According to a US Government-owned(!) document describing the design of Ada: Rationale for the Design of the Ada® Programming Language : A pragma (from the Greek word meaning action) is used to direct the actions of the compiler in particular ways, but has no effect on the semantics of a program (in general). I like the (last caveat) there... This cross references well with on-line greek

First-class value can be passed as an argument returned from a subroutine assigned into a variable. Second-class value just can be passed as an argument. Third-class value even can't be passed as an argument. Why should these things defined like that? As I understand, "can be passed as an argument" means it can be pushed into the runtime stack;"can be assigned into a variable" means it can be moved into a different location of the memory; "can be returned from a subroutine" almost has the same meaning of "can be assigned into a variable" since the returned value always be put into a known

C++ and C# both use the word stream to name many classes. C++ : iostream , istream , ostream , stringstream , ostream_iterator , istream_iterator ... C# : Stream , FileStream , MemoryStream , BufferedStream ... So it made me curious to know, what does stream mean? What are the characteristics of a stream ? When can I use this term to name my classes? Is this limited to file I/O classes only? Interestingly, C doesn’t use this word anywhere, as far as I know. Many data-structures (lists, collections, etc) act as containers - they hold a set of objects. But not a stream; if a list is a bucket,

I'm writing an explanation for some code for a course, and have been accidentally using the words method and function interchangeably. I decided to go back over and fix the wording, but ran into a hole in my understanding. From what I understand, a subroutine is a function if it doesn't act on an instance of a class (its effect is restricted to its explicit input/output), and is a method if it operates on an instance of a class (it may carry out side effects on the instance that make it impure). There's a good discussion here on the topic. Note that by the accepted answer's definitions, a

I am newbie to Java world (7 years of low level plain C). When I started reading Java related sites: http://wiki.apidesign.org/wiki/Main_Page http://static.springsource.org/spring/docs/3.1.x/spring-framework-reference/html/ I confused by existing terminology: class package module component container service framework platform I found many resources about terms definition (and a lot more): Framework vs. Toolkit vs. Library Difference between framework and container? What are the containers in Java Definition of a Java Container http://martinfowler.com/articles/injection.html (Inversion of

What does the term Plain Old Java Object (POJO) mean? I couldn't find anything explanatory enough. POJO's Wikipedia page says that POJO is an ordinary Java Object and not a special object. Now, what makes or what doesn't make and object special in Java? The above page also says that a POJO should not have to extend prespecified classes, implement prespecified Interfaces or contain prespecified Annotations. Does that also mean that POJOs are not allowed to implement interfaces like Serializable , Comparable or classes like Applets or any other user-written Class/Interfaces? Also, does the above

I've seen three ways of doing conversion from bytes to megabytes: megabytes=bytes/1000000 megabytes=bytes/1024/1024 megabytes=bytes/1024/1000 Ok, I think #3 is totally wrong but I have seen it. I think #2 is right, but I am looking for some respected authority (like W3C, ISO, NIST, etc) to clarify which megabyte is a true megabyte. Can anyone cite a source that explicitly explains how this calculation is done? Bonus question: if #2 is a megabyte what are #1 and #3 called? BTW: Hard drive manufacturers don't count as authorities on this one! Andrey Traditionally by megabyte we mean your second