Chapter 4: Programming Language
How to communicate with the computer? Programming language that appeared for this purpose.
Like human communication languages, programming languages also have syntax and semantics and pragmatics three elements.
Although there are exchanges with the computer, but also programming languages Category: machine language, assembly language, high-level language . This may be similar to our Simplified and Traditional or written and spoken language.
| High-level language |
| Assembly language |
| Machine language |
| Computer hardware |
Machine language is away from the computer hardware "recent" language, to binary representation can be directly recognized and executed machine instructions. But it is very inconvenient to use, people use assembly language (symbolic machine language) to replace him, but the high-level language is more similar to natural language than assembly language for the majority of user acceptance.
The computer language has been developing from the very beginning of machine language, assembly language, a variety of procedural programming language that supports object-oriented programming language ...... for the machine is to be able to understand the language very well be able to upgrade to mimic human thinking problems form. Computer language model to solve the problem can be divided into four categories: procedural programming mode (step by step in order), object-oriented programming model (from what to do what to do), functional programming mode (function composition) and explained the formula programming mode (logic) .
Here are some high-level programming languages:
BASIC, PASCAL, C, C ++ , Java ( with C / C ++ distinction: not at all outside the class definition of global variables, without using goto statement, not directly the pointer ), Ada (military), Logo (sub supplied to)
Scripting language (the language of the expansion, dynamic languages): Run interpretation rather than compile and run, save in plain text, interpreted or compiled when it is called.
Chapter V: The data in the computer
Not just data in a digital computer, can all enter the computer and the computer program can be processed symbols are referred to as data.
To be entered into the computer data and computer program for processing, it must be converted into symbols can be recognized by the computer, which requires computer code, computer code has a common ASCII, unicode, UTF-8, GB-2312, an audio coding ( since the audio it is a continuous signal, it is necessary sampling and quantization encoding ) and image coding.
According to some logical data links organized to form structures, it is conducive to treatment. Logical structure data are set, linear structure, a tree structure, and other structure of FIG. I.e., the physical structure of data in the data memory representation relationship, are: sequential storage, chain stores, the index storage and the like. Common data structures: linear form, stacks, queues, trees, FIG ......
Algorithm: substantially complete by the step of solving calculation and predetermined order of operations constituted.
Database: more data is not easy to save, and the data format is different. It is necessary to store the database. Having a data structure, high data sharing, redundancy bottom, easy expansion, high independence, by the unified management and control of database management systems and so on. Database with three mode and the second mapping architecture. Database management system is defined, creating, maintaining a tool database, hardware, software, data, users, procedures, components. Mainstream databases such as: Oracle, Microsoft SQL Server, MySQL and so on.
Data center: for data in a physical space centralized processing, storage, transmission, exchange, management of a complex set of facilities.