Chapter15 Program Design

1. Chapter15 Program Design 程序设计概述

2. Terms and New Words blueprint n.蓝图, 设计图, 计划 vt.制成蓝图, 计划 flow chart 流程图 syntax n.[语]语法, 有秩序的排列, 句子构造, 句法 punctuation n.标点, 标点符号 mechanical adj.机械的, 机械制的, 机械似的, 呆板的 payroll n.薪水册 prerequisite n.先决条件 adj.首要必备的 rudimentary adj.根本的, 未发展的

3. The process of writing an original program begins with problem definition.The programmer’s objective is to identify the desired information,determine the algorithms needed to generate that information,and then define the input data drive the algorithms. 源程序的编写始于问题的定义，程序员的目标是先定义预期得到的输出信息，然后确定产生这种结果的算法，最后决定算法需要的输入数据。 definition n.定义, 解说, 精确度 objective n.目标, 目的, identify vt.识别, 鉴别, 把...和...看成一样 v.确定 desired adj.渴望的, 想得到的 determine v.决定, 确定, 测定, 使下定决心 algorithm n.[数]运算法则

4. Next comes planning, when the basic logical steps needed solve the problem are determined. 紧接着就应认真规划一下解决该问题所需的基本步骤。 plan n.计划, 设计图, 平面图 vt.计划, 设计 determined adj.坚决的, 决定了的

5. Writing a program involves carefully translating the plan to a programming language.The process of removing errors (or bugs) from a program is called debugging.Once a program is completed,maintenance begins. 写程序时应将计划认真地转换成程序语言。排除程序中错误的过程称之为调试，程序一旦测试成功后，就应进行程序的运行维护了。 involve vt.包括, 笼罩, 潜心于, 使陷于 bug n.小虫, 臭虫 v.装置窃昕器, 打扰 debugging n.调试 maintenance n.维护, 保持, 生活费用, 扶养

6. How does a programmer go about modifying a software package? More generally,how does a professional programmer go about the task of writing one or original program? Programming is not quite a science; there is a touch of artinvolved. 一般来说，程序员如何修改软件包呢？更普遍地讲，职业的程序员如何编写原始程序呢？编程序不完全是一门科学，还涉及到一点艺术。 go about v.着手做, 从事, 走动, 传开 art n.艺术, 艺术品, 技术, 巧妙, 美术 involved adj.棘手的,有关的

7. Thus it is not surprising that different programmers work in different ways. Most, however, begin by carefully defining the problem,and then planning their solution in detail before writing the code.Let’s brieflyinvestigate the program development process. 因此，不同的程序员用不同的方法编程序是不奇怪的。然而，大多数程序都从仔细地定义问题开始，然后，在写编码前详细地设计出解决办法。让我们简略地研究一下程序的开发过程。 thus adv.因而, 从而, 这样, 如此 in detail adv.详细地 briefly adv.暂时地, 简要地 investigate v.调查, 研究

8. Problem Definition 问题的定义 The first step is defining the problem.That seems like common sense,but all too often,programs are written without a clear idea of why they are needed.A solution, even great solution, to the wrong problem is useless. 程序开发的第一步是问题的定义，这一点看起来是常识，但常常有些程序在还不清楚为什么需要就编出来了，对一个未能正确定义的问题所得到的结果，即使是一个伟大的结果，也是无用的。 common sense n.常识(尤指判断力) useless adj.无用的, 无效的, 无益的, 无价值的

9. Programs are written because people need information; thus, the programmer begins by identifying the desired information. 因为人们需要信息，才写程序。因此程序员在明确了所希望的信息后才能开始写。 identify vt.识别, 鉴别, 把...和...看成一样 v.确定 desired adj.渴望的, 想得到的

10. Next, the algorithms, or rules, for generating that information are specified.Given the desired information (output) and the algorithms,the necessary input data of what the program must accomplish. 接着要确定产生那个信息的算法或规则。给出了所要求的输出信息和算法，要输入的数据也就确定了。 algorithm n.[数]运算法则 specify vt.指定, 详细说明, 列入清单 desired adj.渴望的, 想得到的 accomplish vt.完成, 达到, 实现

11. Planning 编排 The algorithms define what must be done; the next task is deciding how to do it, the objective is to state a problem solution in terms the computer can understand. 算法确定了必须做的事情，接下来的任务是决定如何去做。目的是要用计算机理解的术语去陈述问题的解法。 objective n.目标, 目的 state n.情形, 状态, 政府, 州 adj.国家的, 国有的, 国营的, 州的, 正式的, 典礼用的 vt.声明, 陈述, 规定 term n.学期, 期限, 期间, 条款, 条件, 术语

12. A computer can perform arithmetic, compare, copy,and request input or output;thus, the programmer is limited to these basic operation. 由于计算机只能完成算术运算、比较、复制和请求I/O等操作，因此程序员受到这些基本操作的限制。 perform vt.履行, 执行, 表演, 演出 v.完成任务 operation n.运转, 操作, 实施, 作用, 业务, 工作, 手术, 军事行动

13. A good starting point is solving a small version of the problem;by actually solving the algorithm,even on a limited scale, the programmer can gain a good sense of the steps required to program it. 一个良好的起点是首先确定求解问题的一个小型方案，通过实际求解的这一算法甚至是规模上有限的一个算法，使程序员获得编程问题所需的步骤。 scale n.刻度,衡量,比例,数值范围,比例尺,天平,等级 gain vt.得到, 增进, 赚到, 开腰槽于 vi.获利, 增加

14. Programmers use a number of tools help convert a problem solution to computer terms. For example, flowcharts can express the logical structure of programs. 程序员可用大量的工具，把一个问题的解法转换成计算机术语。例如，流程图就可以表示程序的逻辑结构。 convert vt.使转变, 转换...,使...改变信仰 structure n.结构, 构造, 建筑物 vt.建筑, 构成, 组织

15. Programmer can draft the logic converting it to source code.More complex programs are often written by two or more programmers, or involve a great deal of logic. 在把它转换成源码之前，程序员能够画出程序逻辑结构的草图。较复杂问题的程序经常由两个或更多的程序员写成，或者包含大量的逻辑关系。 draft n.草稿, 草案, 草图 vt.起草, 为...打样, 设计 convert vt.使转变, 转换...,使...改变信仰 complex adj.复杂的, 合成的, 综合的 n.联合体

16. Such programs are typically broken down into smaller,single-function modules that can be independently coded. A good programmer plans the contents of each module and carefully define the relationships between the modules before starting to write the source code. 这些程序一般被分割成一些较小的单功能模块，能独立地对它们编码。一个好程序员在开始写源码之前规划好每一模块的内容，认真地定义模块之间的相互关系。 module n.模数, 模块, 登月舱, 指令舱 independently adv.独立地, 自立地 content n.内容, 容量, 目录, 满足

17. Just as a contractor prepares detailed blueprints before starting to build house,a programmer develops a detailed program plan before starting to write code. 正像一个承包人在开始建房之前，准备好详细的蓝图。程序员在开始写程序之前也要制定出一个详细的编程计划。 contractor n.订约人, 承包人 develop vt.发展, 发达, 发扬, 进步, 逐步展开 vi.发展, 生长, 发育, 逐步显示出来