Programme Testing

Question 1

What is testing?

Answer 1

Testing is the process of running a program to try and ascertain if the program is working as intended.

Question 2

what are the 3 considerations needed when finding how well a program is built?

Answer 2

Protection against unexpected user inputs or actions, authenticating that users on a computer system are who they say they are, minimising or removing errors and bugs.

Question 3

What are the main classes of error?

Answer 3

Syntax error, runtime error and logic error.

Question 4

What are syntax errors?

Answer 4

Syntax errors occur when the code given does not follow the syntax rules of a particular language program.

Question 5

What are some non-exhaustive reasons for syntax errors?

Answer 5

• misspelling keywords or statements
• missing or incomplete pairs of parantheses

Question 6

What are logic errors?

Answer 6

A logic error is an error that causes a program to not accomplish its intended and expected goal.

Unlike a syntax error, the logic error does not stop the program from running. The program will run, but not deliver the intended outcome as expected.

Question 7

What are some reasons that result in logic errors?

Answer 7

• Incorrect program design
• Using the same identifier name for different purposes
• Incorrect range used in terminating conditions

Question 8

What are run time errors?

Answer 8

They are errors that occur during the execution of a program.

Question 9

What are some reason for run time errors?

Answer 9

• Performing an operation on incompatible types
• Performing an incorrect mathematical equation
• Reading a file that does not exist

Question 10

Is a syntax error considered a run time error?

Answer 10

No. At the complication stage, the syntax errors are detected as the process would fail without proceeding to the next stage. However, run time errors happen at any time throughout the stages.

Question 11

What is test data?

Answer 11

Test data is data that is used to test if a program is functioning as it is intended to be.

Question 12

What are the different types of test data?

Answer 12

Normal (valid data), boundary (extreme data), abnormal (erroneous data)

Question 13

What is normal test data?

Answer 13

It is typical data values that are valid.

Question 14

What is boundary test data?

Answer 14

It is test data at the upper or lower limits of expectations that should be accepted by the system.

Question 15

What is abnormal test data?

Answer 15

It is data values that the system should fail or not accept.

Question 16

What are some factors to consider in the design of test plans?

Answer 16

The requirements of the system, the performance of the system against the original design, the pathways through the system, validation routes.

Question 17

What is a desk check / dry run?

Answer 17

It is the process of using data chosen by the checker to trace through the logic of the algorithm keeping track and recording the values of variables and printed output in a trace table with an intention to identify potential logic errors.

Question 18

What is a trace table?

Answer 18

It is a table with a column for each variable that records their changing values.

Question 19

What are the advantages of desk checking?

Answer 19

• Running a desk check is quick and inexpensive
• Allows the programmer to code the algorithm and at the same time perform checks on his algorithm so that errors can be sifted out

Question 20

What are the disadvantages of desk checking?

Answer 20

• Desk check is subjected to human error too
• A desk check does not guarantee that a programmer will find mistakes
• Getting another individual to perform checking on an algorithm requires time for the checker to first understand the algorithm