文档介绍：Programming Languages (程序设计语言)
./~course/cs101/2013
Hongfei Yan
School of EECS, Peking University
10/9/2013
2
Evolution
Evolution puter languages
3
计算机语言的演化
机器语言
指令由0和1串组成, 程序可直接执行
符号语言
用符号表示不同的机器语言指令,必须被汇编(assembler)为机器语言
高级语言
从关注计算机转移到关注问题本身. 用语句(statement), pile)或解释(interpret)执行.
4
Computer language
The puter language includes a large variety of artificial languages used municate puters.
It is broader than the monly-used term programming language.
Programming languages are a subset puter languages.
For example, HTML is a markup language and puter language, but it is not traditionally considered a programming language.
Machine code is puter language.
It can technically be used for programming, and has been (. the original bootstrapper for Altair BASIC),
though most would not consider it a programming language.
5
Types puter Languages
Programming languages
are the primary means by which developers puting systems instruct a machine anize or manipulate information or control physical devices.
Most software is written using one or more programming languages.
Common examples include C, C++, Java, BASIC, assembly languages, and many others.
Scripting languages
are designed to control other software or to coordinate the actions of multiple software applications.
Machine code
a non human-readable puter language which corresponds to the available instructions for a microprocessor.
……
6
What problem gave birth to programming languages?
Before high level programming languages existed,
computers were programmed one instruction at a time using binary or hex.
a tedious job and a lot of errors.
Obviously, this job did not attract many people, so there was a shortage of programmers.
puters sat idle for long periods of time while software was being developed.
Software often cost two to four times as much as puter.
This led to the development of assemblers and assembly languages.
Programming became somewhat easier,
but