Types of errors.

Text A System errors affect the computer or its peripherals. For example,

you might have written a program which needs access to a printer. If there is no printer present when you run the program the computer will produce a system error message. Sometimes a system error makes the computer stop working altogether and you will have to restart the computer. A sensible way of avoiding system errors is to write code to check that peripherals are present before any data is sent to it. Then the computer would warn you by a simple message on the screen, like 'printer is not ready or available'.

Text В Syntax errors are mistakes in the programming language (like typing

PRNIT instead of PRINT). Syntax errors cause the program to fail. Some translator programs won't accept any line that has syntax errors. Some only report a syntax error when they run the program. Some languages also contain special commands such as debug, which will report structural errors in a program. The programming manual for the particular language you're using will give details of what each error message means.

Text С Logic errors are much more difficult to detect than syntax errors.

This is because a program containing logic errors will run, but it won't work properly. For example, you might write a program to clear the screen and then print 'hello'. The code has a logic error in it, but the syntax is right so it will run. You can get rid of logic errors from simple programs by “hand testing” them or doing a 'dry run' which means working through each line of the program on paper to make sure it does what you want it to do. You should do this long before you type in the code.

Ex.2 Problem and solution.

Study these ways of linking a problem and a solution.

Problem: get rid of logic errors Solution: hand-test the program

You can get rid of logic errors by hand-testing the program. To get rid of logic errors, hand-test the program.

Match these problems and solutions. Link them following the examples above

Problems

1. connect a computer to a telephone line
2. identify items for pricing
3. add extra facilities to a computer

4. get more file storage space

5. find syntax errors

6. avoid marking the surface of a CD-ROM

7. improve the speed of your computer

8. avoid system errors

9. prepare a new disk for use

10 transfer information between computers

Solutions

a write code to check a peripheral is present before any data is sent

b use the debug command

с add more memory

d format the disk

e use a removable disk

f install an expansion card

g install a modem h fit a bigger hard disk

i use barcode labels

j hold it by the edges

Ex.3 Translate these sentences into English:

1. Чтобы избавиться от логической ошибки, нужно протестировать программу вручную.
2. Чтобы избежать от системной ошибки, напишите код и проверьте, включены ли периферийные устройства.
3. Синтаксические ошибки приводят к сбою в программе.
4. Мне пришлось перезагрузить компьютер, потому что он перестал работать («завис»).
5. Удостоверьтесь, включен ли сканер.
6. В этом учебнике (справочнике) написано, как обнаружить и устранить ошибки в программах.

Ex. 4 Make your own sentences using the words from the vocabulary list.

Vocabulary

Text 19

Read the interview.

Date: 2015-01-12; view: 800