Source:
"Code Daquan"
It is important to realize the system's language, because from the beginning of the creation, you must immerse it.
Studies have shown that program language selection can affect productivity and coding quality through several aspects.
When the programmer uses the language you are familiar with, its work efficiency is much higher than the use of unfamiliar language. TRW
Data indicates that two levels and experience comparable programmers can use a three-year language programming, and another
Use a language of his strange language, then the former is 30% higher than the latter. IBM survey shows that one is in a certain
Language experienced programmer, its efficiency is three times higher than the programmer who has no experience in this language (Walston
And Felix 1977).
Programming with advanced languages, its efficiency and quality are much higher than using low-level languages. Pascal and Ada language efficiency,
Reliability, simplicity, and understandable are low-level languages, such as 5 times the compilation and machine language (Brooks 1987). Because not
The times cheer for the machine correctly, you can certainly save a lot of time. At the same time, high-level language expressions
It is high than the low language, so that each line of code can express more content. Table 3-2 gives the same amount of code
In the case where the original instructions expressed by the advanced language are represented by the lower-level language (represented by assembly language).
IBM's data indicates how language characteristics affect efficiency from another aspect, using programs that explain language work
The staff tend to be more efficient than programmers working in compile language (Jones 1986). Many languages have two kinds of interpretation and compilation
Forms (such as multiple versions of C language), you can use high-efficiency explanations, then convert them into more easily
Compilation form.
Some languages are more good at explaining programming ideas than other languages. You can put natural language (such as English) and program language (eg
Pascal and assembly language) comparison. In the natural language, the imaginary expectations present in the linguist Sapir and Whorf pointed out in one
There is a connection between the expression of language and the problem they can think, and the ability you think about a certain issue depends on what you understand.
Get the vocabulary of this problem. If you don't understand those vocabulary, you can't express those thoughts, you even have
Method forming those thoughts.
Programmers may also be limited by the programs he know. The vocabulary you know in a program language,
Of course, you will decide how you express your programming idea, it is also likely to determine what kind of idea you will express.
Program language affects programmers' ideological methods. A typical story says this: "We are using Pascal language development
A new system, but our programmers are not familiar with the Pascal language, they are engaged in the Fortran language. Knot
As they write, they are compiled with PASCAL, but they really use the deformed FOTRAN language. They use
Fortran 's bad features (GOTO statements and global data) distorted Pascal language, while also putting Pascal's rich control
The system is not in use. "This phenomenon has a report throughout the software industry (Hanson 1984, Yourdon 1986).
3.5.1 Language Description
The development history of certain languages is as interested as its generic functions. The following is about some routines raised in this book.
Description of the language that appears.
ADA language
It is a universal high-end language developed on the PASCAL language, which is developed under the requirements and funding of the Ministry of Defense.
It is especially suitable for real-time and embedded systems. ADA emphasizes data abstraction and information concealment, forcing you to distinguish between modules.
Partial part.
Naming this language "Ada" is to commemorate the ADA Loveland, which is recognized as the world's first programmer, from 1986, all key tasks in NATO and the Ministry of Defense use ADA Language.
Assembly language
As a language, it is a low-level language, and each statement corresponds to a machine directive. Since the statement uses specific
Machine commands, so assembly language is for specific processors, such as Intel 80x86 or Motoraala 680x0. Assembly is
The second generation of computer languages unless the need to perform speed or code space, most of the programmers avoid using it.
Basic language
Basic is a high-level language developed by the Dartmouth College John Kemeny and Thormas Kurtz. Word header
The composition of Basic is the beginner's full-featured symbol instruction code (BASIC), Basic is mainly used for teaching students. Since the IBM-PC contains it, it is in the center of the microcomputer
At the time, Basic is originally an explanatory language, and there are two forms of interpretive and compilerics.
C language
C is a intermediate universal language that is originally related to the UNIX operating system. C has some of some advanced languages, examples
For example, structured data, structured control flow, independence of machines, rich operation instructions, etc. It is also called "shifted"
Assembly language, because it has widely used pointers and addresses, with certain low-level components, such as bit operation, and
Weak type.
C is developed in the 1970s by Bell Lab Dennis Ritchie. C is originally designed for DEC PDP-11,
Its operating system, C compiler, and UNIX applications are written in c. In 1988, ANSI announced C code
Standard, this is a general standard for microcomputer and workstation programming.
C language
C is an object-oriented language, similar to C, Bjarne Stroustrus, Bell Laboratory.
In addition to C-compatible, C provides polymorphism and function overload function, and it provides a stronger than C.
Type check function.
Fortran language
Fortran is a high-level language, introducing variables and advanced cycles. Fortran represents Formula Translation,
The meaning of formula translation. Fortran was originally developed by Jim Bckus in the fifth year and has made several major amendments. package
Including the FOTRAN-77 published by 1977, which adds block structured if-kilse statements and string operations.
The Fortran-90 increases the user-defined data type, pointer, module, and rich array operations. When writing this book (1992
At the end of the year). The Fortran standard is so triggering, in order to cause most of the language vessels fail to finalize it. This book is incorporated herein by reference
The Fortran-77 standard. The Fortran language is mainly used in science and engineering calculations.
Pascal language
Pascal is a high-level language developed for teaching purposes. Its main feature is strict type, structured control creation and
Structured data type. It was developed by Niklaus Wirth at the end of the 1960s, in 1984, due to Borland International
The company introduced the low-cost compiler of the microcomputer, and Pascal is popular.
3.5.2 Language Select Quick Reference Table
Table 3-3 shows a short reference to the scope of applicable scope of different languages. It can also help you choose a language that should be further understood. However, do not try to use it to replace a detailed assessment of language selection for your particular plan. The following sort is
It is rough, so you should be carefully distinguished when reading it, because there are many exceptions.
