Of the 1,000 or so computer languages that have been developed, each language can be categorized based upon the following criteria:
- Low-level or High-level
- Procedure-oriented or Event-oriented
- High-visual or Low-visual
- Interpreted or compiled
Imagine 1,000 or so languages! Where does Visual Basic fit? This section helps to explain not only where Visual Basic fits, but why it is different from many other programming languages.
Low-level and High-level Languages
A computer language can be described as a low-level or high-level language based on how close the language is to machine language (which depicts a low-level language) or to English (which depicts a high-level language). Let’s look at what we mean by this difference in language.
Low-level languages are machine oriented. These languages work close to machine language, which is limited to 0s and 1s. Why only 0s and 1s? This is the language the computer understands or it works by turning electronic circuits Off (0) and circuits On (1). By making a language closer to 0s and 1s, the speed at which the computer processes data improves.
An example of a low-level language is assembly language code. With this language, such instructions as the following tell the computer to save, move, add and store the results of processing:
PUSH BX PUSH AX MOV AX, @A MOVE BX, @B ADD BX, AX MOV @B, BX POP BX POP AX
Assembly language code uses mnemonics (memory aids), for which such words as ADD and POP make it easier to remember what an assembly instruction does. While not quite 0s and 1s, you deal with the exact steps the computer must take in processing data when programming in assembly language.
Low-level languages are said to have one-to-one relationship with the computer. A programmer must write an explicit instruction for every operation of the machine. A low-level language is precise. Programmers use low-level language code for such tasks as writing operating systems (the software that enables your computer to operate).
High-level language are more people-oriented. These languages have a one-to-many relationship, in which one instruction leads to a series of machine-level instructions. These languages feature more English and English-like words. In Visual Basic, examples of these English-like words are If, Else, Dim (for dimension), and OpenDatabase.
Because of this one-to-many relationship, high-level languages are easier to learn, use and understand. However, they do require more machine time to translate a single instruction into a set of machine-level instructions.
Programmers (those who write computer programs) use high-level languages in writing application programs. For example, a high-level language, such as Visual Basic, would be used to write the instructions for processing a company payroll. Application programs define the ways by which users are able to use the computer.