Thirdgeneration languages highlevel languages

Third-generation languages (3GL), also became known as high-level languages and were written in such a way that single statement would be converted into several low level machine instructions. A translator program would then be used that would convert the high-level instructions into machine language. Such a program is called a compiler although some languages - VB included - use an interpreter (interpreters will be discussed later in the chapter). A compiler is a program that translates high-level source code into machine language and creates an executable file: i.e. a file that can be executed directly from the operating system.

Many 3GLs were developed for special purposes, and began to appear in the mid-1950s. FORTRAN (FORmula TRANslation) was the first of the crop developed by IBM in 1954 for scientific purposes. COBOL (COmmon Business Oriented Language) was developed in 1959 for commercial applications. Pascal, developed in 1971, was primarily developed for educational purposes. A variety of high-level languages were created for different kinds of tasks. Each one provides different kinds of abstractions for the different tasks they were created to solve. Thus, FORTRAN was strong on scientific abstractions and number crunching, making it an ideal scientific language. COBOL on the other hand was very strong on file handling and reporting; making it an ideal business language. Pascal was strong on structured programming to facilitate good program practice and therefore became popular as an educational language. C was another very popular general purpose high-level language. The thing that made C so popular was that it provided low-level language and high-level facilities making it relatively fast to compile programs.

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