Error/Exception Handling and Testing/Debugging

Question 1

Define Logic

Answer 1

the order in which parts of code execute/run

Question 2

Define Syntax Error/Parse Error

Answer 2

the scripting engine fails to recognise code

Question 3

Define Run-Time Error

Answer 3

the scripting error encounters an error while the program is executing

Question 4

Define Logic Error

Answer 4

scripting engine doesn’t behave as it should

Question 5

What are the three categories of error types?

Answer 5

notice
warning
fatal

Question 6

What is a Notice error type?

Answer 6

a harmless problem. Can be involved using explicit programming

Question 7

What is a Warning error type?

Answer 7

something is clearly wrong and action should be taken

Question 8

What is a Fatal error type?

Answer 8

something has gone terribly wrong and processing cannot continue

Question 9

what does error_reporting do?

Answer 9

says which types of error messages PHP should generate

Question 10

what does log_errors do?

Answer 10

PHP logs errors into a file. Is assigned the default value “off”

Question 11

display_errors

Answer 11

prints errors to screen (stdout) and could be assigned to stderr

Question 12

display_startup_errors

Answer 12

displays errors that occur when PHP first starts. Assigned to default value “off”

Question 13

What is the structure of an error handler?

Answer 13

error_function_name(error_level, error_message, error_file, error_line, error_context)

Question 14

which two attributes are required in an error handler?

Answer 14

error_level and error_message

Question 15

what does error_level do

Answer 15

specifies error report level for user_defined errors. Must be a value number

Question 16

error_message

Answer 16

specifies the error message

Question 17

error_file

Answer 17

specifies which file the error occurred in

Question 18

error_line

Answer 18

specifies line number the error occurred in

Question 19

error_context

Answer 19

specifies an array containing every variable and their values that were in use when the error occurred

Question 20

What is an exception?

Answer 20

Something that is used to change the normal flow of the code execution if a specified (exceptional) error condition occurs

Question 21

What normally happens when an error is triggered?

Answer 21

current code state is changed, OR
code execution will switch to a predefined (custom) exception handler function, OR
depending on the situation, the handler may:
- resume execution from saved code state
- terminate the script execution
- continue script from a different location of the code

Question 22

What is a Try block

Answer 22

Contains the function using an exception
If the exception doesn’t trigger, code continues as normal
If it does, exception is thrown

Question 23

What is Throw

Answer 23

how you trigger the exception

each throw must have at least one catch

Question 24

What is Catch

Answer 24

retrieves an exception and creates an object containing exception information

Question 25

What are the four attributes of the exception class?

Answer 25

message : the exception message

code: the exception code
file: the filename where the exception was created
line: line where exception was create