UNIT 4 - chapter 9

Question 1

Assembly language

Answer 1

• The programmer must manually manage the movement of data items between and among memory locations and registers ( although such data items can be assigned mnemonic names).
• The programmer must take a microscopic view of a task, breaking it down into tiny subtasks at the level of what is going on in individual memory locations.
• An assembly language program is machine specific.
• Statements are not natural-language-like(although operations are given mnemonic code words as an improvement over a string of bits).

Question 2

High-level language ( expectations)

Answer 2

The programmer need not to manage the details of the movement of data items within memory or pay any attention to exactly where those items are stored.
The programmer can take a macroscopic view of tasks, thining at a higher level of problem solving ( add B and C, and call the result. A) The “primitive operations” used as building blocks in algorithm construction can be larger.
Programs are portable rather than machine specific.
Programming statements are closer to natural language and use standard mathematical notation.

Question 3

High-level programming languages are often called

Answer 3

third-generation languages.

Question 4

Compiler

Answer 4

A translator that converts high-level language instructions into machine language instructions.

Question 5

high-level language instructions are

Answer 5

usually the source code

Question 6

linker

Answer 6

a system software that inserts requested object code from code libraries into the object code for the requesting program.

Question 7

procedural languages ( also called imperative languages)

Answer 7

A program written in a procedural language consists of sequences of statements that manipulate data items. The programmer’s task is to devise the appropriate step-by-step sequence of “ imperative commands” - instructions in the programming language - that, when carried out by the computer, accomplish the desired task.

Question 8

the syntax and semantics of high-level languages

Answer 8

rules ( syntax) for exactly how statements must be written and the meaning ( semantics) of correctly written statements.

Question 9

software development life-cycle

Answer 9

the overall sequence of steps needed to complete a large-scale software project.

Question 10

Steps in the software development life-cycle

Answer 10

1) Before implementation
- Feasibility study
- Problem specification
- Algorithm selection or development, and analysis
2) implementation
- coding
debugging
3) Aftern implementation
- testing, verification, and benchmarking
- documenting
- maintenance

Question 11

Feasibility study

Answer 11

evaluates a proposed project and compares the costs and benefits of various solutions.

Question 12

Problem specification

Answer 12

involves developing a clear, concise, and unambiguous statement of the exact problem the software is to solve.

Question 13

Problem specification document

Answer 13

expresses the final and complete problem specification and guides the software developers in all subsequent decisions.

Question 14

Program design phase

Answer 14

the time to plan how it is to be done

Question 15

divide-and-conquer ( also called top-down decomposition)

Answer 15

tasks are broken down into subtasks which are broken down into sub-subtasks and so on until each piece is small enough to code comfortably. These pieces work together to accomplish the total job.

Question 16

Objected-oriented approach to program design

Answer 16

the appropriate objects are identified, together with their data and the subtasks they must perform. This allows classes to be designed with variables to store the data, and functions ( also called methods) to carry out these subtasks. Objects from these classes cooperate to accomplish the total job.

Question 17

Coding

Answer 17

the process of translating the detailed designs into computer code.

Question 18

Debugging

Answer 18

is the process of locating and correcting program errors.

Question 19

runtime errors

Answer 19

occur only when the program is run using certain sets of data that result in some illegal operation, such as dividing by zero.

Question 20

logic errors

Answer 20

These are errors in the algorithm used to solve the problem.

Question 21

empirical testing

Answer 21

an approach to design a special set of test cases, called a test suite and run the program using this special test data.

Question 22

Unit testing

Answer 22

takes place on each module ( subtask code) as it is completed.

Question 23

Integration testing

Answer 23

is done to see that the modules communicate the necessary data between and among themselves and that all modules work together smoothly.

Question 24

regression testing

Answer 24

is done to be sure that this change hasn’t introduced a new error into code that was previously correct.

Question 25

Program verification

Answer 25

can be used to prove that if the input data to a program satisfies certain conditions, then, after the program has been run on these data, the output data satisfies certain other conditions.

Question 26

Benchmarking

Answer 26

the program means running it on many data sets to be sure its performance falls within those required limits.

Question 27

Documentation

Answer 27

Program documentation is all of the written material that makes a program understandable. Includes:

• internal documentation, which is part of the program code itself.
• External documentation consists of any materials assembled to clarify the program’s design and implementations.
• Technical documentation enables programmers who later have to modify the program to understand the code.
• User documentation helps users run the program.

Question 28

Program maintenance

Answer 28

the process of adapting an existing software product, may consume as much as 65% of the total software development life cycle budget. If the program has been well planned, carefully designed, well coded, thoroughly tested, and well documented, then program maintenance is a much easier task.

Question 29

Integrated development environment ( IDE)

Answer 29

lets the programmer perform a number of tasks within the shell of a single application program, rather than having to use a separate program for each task.

Question 30

Sample graphical user interfaces ( GUIs) called prototypes

Answer 30

Many IDE’s enable programs to create prototypes that can be shown to prospective users in the initial stages of software development.

Question 31

waterfall model of software development

Answer 31

the name given to the step by step software development life cycle

Question 32

agile software development

Answer 32

is a set of methods and practices where solutions evolve through collaboration between self-organizing, cross-functional teams.
In software development, agile is a set of practices intended to improve the effectiveness of software development professionals, teams, and organizations

Question 33

Pair programming

Answer 33

involves two programmers at a single workstation