Error/Exception Handling and Testing/Debugging Flashcards
Define Logic
the order in which parts of code execute/run
Define Syntax Error/Parse Error
the scripting engine fails to recognise code
Define Run-Time Error
the scripting error encounters an error while the program is executing
Define Logic Error
scripting engine doesn’t behave as it should
What are the three categories of error types?
notice
warning
fatal
What is a Notice error type?
a harmless problem. Can be involved using explicit programming
What is a Warning error type?
something is clearly wrong and action should be taken
What is a Fatal error type?
something has gone terribly wrong and processing cannot continue
what does error_reporting do?
says which types of error messages PHP should generate
what does log_errors do?
PHP logs errors into a file. Is assigned the default value “off”
display_errors
prints errors to screen (stdout) and could be assigned to stderr
display_startup_errors
displays errors that occur when PHP first starts. Assigned to default value “off”
What is the structure of an error handler?
error_function_name(error_level, error_message, error_file, error_line, error_context)
which two attributes are required in an error handler?
error_level and error_message
what does error_level do
specifies error report level for user_defined errors. Must be a value number
error_message
specifies the error message
error_file
specifies which file the error occurred in
error_line
specifies line number the error occurred in
error_context
specifies an array containing every variable and their values that were in use when the error occurred
What is an exception?
Something that is used to change the normal flow of the code execution if a specified (exceptional) error condition occurs
What normally happens when an error is triggered?
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
What is a Try block
Contains the function using an exception
If the exception doesn’t trigger, code continues as normal
If it does, exception is thrown
What is Throw
how you trigger the exception
each throw must have at least one catch
What is Catch
retrieves an exception and creates an object containing exception information
What are the four attributes of the exception class?
message : the exception message
code: the exception code
file: the filename where the exception was created
line: line where exception was create
