Computer Programming Basics
A computer is not very intelligent. In fact, the computer cannot do anything at all until a person gives it the instructions and tells it what to do. Those instructions come in the form of different types of computer programming languages. There are thousands of computer languages, but they can be grouped by how complex the instructions are in relation to what the computer can understand.
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Logical Instructions
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In order to program a computer, you must think and write clearly and logically. A computer can only do exactly what you tell it and cannot make assumptions. It is often difficult to think in very clear and detailed ways to ensure the computer knows what you want, which is what makes computer programmers valuable. The computer will only do exactly what you ask it to do, and will never do any more.
Machine Language
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Machine language is the basic language that the computer understands. Machine language consists of nothing but a long combination of zeros and ones. All other programming languages and computer instructions have to be converted into machine language in order for the computer to process the instructions. Few people ever actually write program in machine language because it is so difficult for people to understand. Instead, there are usually programs that convert other programming languages into machine language.
Assembly Language
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The next level "up" from machine language is assembly language. This computer programming language is still considered a low level language because the computer can understand the language rather easily. Assembly language is a series of short 3-letter commands. Assembly language is still very difficult to use to program a computer, because it takes a large number of 3-letter commands to do even a simple task for the computer.
High Level Languages
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Most people who program computers use high level languages. Many people who start out in computer programming use a program called Visual Basic, which is a high level language. High level programming languages are easier for humans to understand, but impossible for computers to understand. Instead, an interpreter or compiler is used to convert the high level programming language into machine language so the computer can understand it. High level languages can still be very complex.
Fourth Generation Languages
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Fourth Generation Languages (4GLs) are an attempt to make computer programming even easier. While high level languages are easy for experienced computer programmers to understand, fourth generation languages are designed to be used by people without computer programming experience. These programming languages are designed to respond to natural English speaking instructions which are converted to machine language so the computer can understand them. Because of the complexity of the English language, few fourth generation programming languages are effective.
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