Programming Languages A programming language is a set of English-like instructions that includes a set of rules for putting the instructions together to create commands. A translator changes the English-like commands into numeric code that the computer can understand. The most common type of translator is a compiler. The compiler is program that reads English-like commands in a file and than creates another file containing computer readable numeric code or commands. I will be talking about some of the major functions and uses six high-level programming languages.
Java was developed by Sun MicroSystems and released in 1995. Java is based on C and C++ and incorporates many features object-oriented languages. It is a compiled language, but its code output is interpreted. This makes Java ideal for cross-development. The downside to its interpreted code is speed.
Javas object-oriented is fundamental, and all code and data in a Java program exist within the object-oriented class. Javas exception handiling with try, catch, and throw statements provide the solution for writing reliable code that responds to all possible error conditions. Another advantage of Java is a String class that does away with null-terminated, length byte and other types of strings. It is also multithreaded which a class can easily provide code that runs concurrently with other programing. Another advantage is the lack of a pointer-type data and memory management which tends to be a very bug-prone area. Memory is organized by Javas virtual machine garbage collector. Java provides a rich class library in beavery bug-prone area. Memory is organized by Javas virtual machine garbage collector.
Java provides a rich class library in the forms of packages imported into modules. Since Java is interpreted locally on the users system, a security manager can completely control disk access, window creation, and memory management. C was developed by Dennis Ritchie at Bell Labortories in 1972. C was originally designed as symbolic code that formalized programming prasctices used at the time. In 1978 C blossomed into what was to become the most popular programming language ever.
C offers programmers three advantages: The first is general pourpose programming which allows you to write games, business software, utilities, mathematical models, wordprocessors, spredsheets, and other kinds of software. The second is structured programming which means it uses structured statements such as while and for loops in place of goto statements that are easily misused. Third is that its a standardized programming language, which is ANSI C, the reconized standard for programming language. C++ was developed by Bjnarnte Strounstrip in the early 80s at Bell Labortories. It is an object-oriented programming language which contains three elements: First is encapsulation which extends the capacity of modularity. Second is polymorphism which is the use of a name or symbol.
Third is inheritance which allows the designer to take existing objects and create new ones that inherit the properties of an earlier object. Objects are created in C++ through the mechanism of the class which is a data type similar to the C structure. However it differs from the C structure in many important ways. The most important is that it not only contains varible numbers, but also function numbers which are the methods that act on the varible numbers. C++ class also contains two basic sections, a private section and a public section. A private sectons is parts of a class that are available to member functions but that cannot be accessed from outside the function.
A public section defines the interface between the class object and the rest of the program. The class data type is the focus of C++, everyting in the language revolves around this user-defined data type. C++ is a evolutionary step up from C, much of its syntax is identical to that of C. Some of the basic features and syntax that are shared by both are The Main( ) function, the use of function arguments,arithmetic and logical operators, control and looping statement, Bit wise communication, and basic data types. Visual basic evolved from BASIC.
It was created by Microsoft Corporation in 1991. Visual basic is an example of a graphical-based language which allows the user to directly work with graphics. It is created in an Integrated Development Enviorment (IDE). IDE allows the programmer to run, debug, and create Visual basic programs convienietly. It also allows programmers to make programs in fraction of the time it would normally take.
Visual basic is also the most widely used Rapid Application Development language which is the process of rapidly creating an application. Its an event-driven language that does not follow a defined sequence of instructions. It responds to events to execute different sets of instructions depending on which event occurs. Visual basic is also an object-oriented language, it uses identifiable shapes, each of which has certain properties and can respond to a variety of events. Cobol is a programming language especially aimed at solving business problems and can be used as a solution to many data processing problems.
Cobol was developed by the conference on Data Systems Languages convened in 1959 byu te Department of Defense. Approximatly 90% of all Cobol code runs in character based enviorment and contains no grahics. A Cobol program is made up of four mandatory divisions: The Identification division which marks the beginning of a Cobol program. Second is the Enviorment division which contains statements or commands to describe the physical enviorment in which Cobol is running. Third the Data division which contains statements describing the data used by the program. Lastly the Procedure division which contains the Cobol statements that the program will execute after the program stars running. A Cobol source code file has five areas extending from left to write across the page.
The first six chracters of a line are called the sequence number area. This area provides with warning that numbers are out of sequence. Cobol has a certain minimum amount of code that is required for all programs, this is usually called a shell program. Delphi is a Rapid Application progarm which now progrrammers can use tools which are more intuitive and visual. Delphi uses Object Pascal as its foundation language, which has been one of the fastest compilers in the business.
Also object-based extensions has been added to the language to support good programming practices and efficent code. Delphi is capeble of using OCX controls, which is a 32-bit OLE-based custom control. Delphi also allows you to create OLE automation servers and clients. These automation objects give you the flexibility of creating programs that perform tasks in the backround and put the results back to your application. Anoter advantage for Delphi is the ability to write multi-threaaded applications.
In a multi-tasking enviorment thi is important, as your applications become more comple, it is necessary to execute your applications in seprate pieces, which are called threads. In conclusion, the following was an overview of six high level languages. Many are similar, but there are very distinct features and advantages to each language.