Chapter 9 - Debugging – what goes wrong and how to fix it

Question 1

describe
regression errors

Answer 1

An error found in older code when developing new code.

this can occur when legacy code does not work with new data or was never properly tested to begin with.

Question 2

decsribe
Compilation errors

Answer 2

An error detected by acompilerwhen code iscompiled.

Nobytecode (.class)is generated if these are present.

Question 3

describe
IndexOutOfBoundsException

Answer 3

created when we try and access an index that is out of bounds such as on an ArrayList

Question 4

What are the
basic format specifiers
in formatting strings?

Answer 4

these include:
1. %c for a Unicode character
2. %d for an integer
3. %e for scientific notation
4. %f for a decimal (floating-point) number
5. %s for a string
6. %x for hexadecimal numbers.

Question 5

what are 4 ways to
test input and output data

Answer 5

methods include:
1. documenting
2. positive testing
3. negative testing
4. boundary testing

Question 6

What is a
Template String
in formatting strings?

Answer 6

this is a string that contains format specifiers, where the format specifiers will be replaced by a given input and will follow the rules of the format specifier.

Question 7

describe
Syntax Error

Answer 7

An error that occurs when the source code does not follow the syntax rules of the programming language.

Question 8

describe the debugging method
Manual Walkthrough

Answer 8

A process of going through a section of code line by line to understand how each line affects the state of the object or other parts of the application.

Question 9

describe
positive testing

Answer 9

Using known and valid inputs to check that code produces expected outputs.

Question 10

think of 4 possible fixes for the
“Cannot Find Symbol” Error

Answer 10

fixes for this error inclue:
1. Fix the spelling of the variable name.
2. Add a local variable to a method or constructor.
3. Add a parameter to a method or constructor.
4. Add a field to the class.

Question 11

describe
NumberFormatException

Answer 11

created to indicate that a method that converts a string to one of the numeric types has been passed an argument with an inappropriate format

Question 12

these include:
1. %c for a Unicode character
2. %d for an integer
3. %e for scientific notation
4. %f for a decimal (floating-point) number
5. %s for a string
6. %x for hexadecimal numbers.

Answer 12

What are the
basic format specifiers
in formatting strings?

Question 13

describe
StackOverflowError

Answer 13

created when a program repeatedly calls methods until there is no stack space left to store the state of all the method invocations.

Question 14

these include:
1. System.out.printf()
2. String.format()

Answer 14

which two
options are available in java to format strings

Question 15

describe
Semantic Error

Answer 15

An error that is caused by violating higher-level relationships between parts of code, rather than incorrect syntax.

Question 16

methods include:
1. documenting
2. positive testing
3. negative testing
4. boundary testing

Answer 16

what are 4 ways to
test input and output data

Question 17

describe
NullPointerException

Answer 17

created when you try to call a method using a reference variable whose value isnull

Question 18

what are 2 approaches that try and
prevent the misuse of code by programmers

Answer 18

two approaches that prevent this are:
1. Design by Contract
2. Defensive Code

Question 19

fixes for this error inclue:
1. Fix the spelling of the variable name.
2. Add a local variable to a method or constructor.
3. Add a parameter to a method or constructor.
4. Add a field to the class.

Answer 19

think of 4 possible fixes for the
“Cannot Find Symbol” Error

Question 20

Errors that only become apparent when a program is run, and have not been detected beforehand.

theseerrors can be caused by logical errors or conditions outside of the control of the programmer.

Answer 20

describe
Runtime errors

Question 21

describe
Boundary Testing

Answer 21

Testing with values at and near the extreme values of data fields and collection sizes.

can prevent an error known as an “off-by-one error”

Question 22

Chapter 9 glossary quiz

Answer 22

ignore

Question 23

think of 6 possible examples
semantic errors

Answer 23

examples of this include:
1. Unreachable statements: return x + y; y++;
2. Using an incompatible type of argument in a method call
3. Using an incompatible type of operand with an operator
4. Failing to initialize a local variable before it is first used.
5. Return types not defined correctly
6. Missing variables

Question 24

points include:
1. Occur during the execution of the bytecode
2. Can occur soon after execution or go unnoticed for years
3. Can be detected by JVM or programmer, but some may not signal their presence
4. Result from logical errors, misuse of library code, or failure to take into account software usage
5. May also occur due to reasons out of the programmer’s control such as deleted files, internet failure, JVM failure, or timing errors with the larger system.

Answer 24

think of 5 points about
runtime errors

Question 25

An error that occurs when the source code does not follow the syntax rules of the programming language.

Answer 25

describe
Syntax Error

Question 26

this is a string within a template string that defines rules of how it will be replaced by a variable.

Answer 26

What is a
Format Specifier
in formatting strings?

Question 27

this is a string that contains format specifiers, where the format specifiers will be replaced by a given input and will follow the rules of the format specifier.

Answer 27

What is a
Template String
in formatting strings?

Question 28

An error found in older code when developing new code.

this can occur when legacy code does not work with new data or was never properly tested to begin with.

Answer 28

describe
regression errors

Question 29

what are two common
compile time errors

Answer 29

these include:
1. syntax errors
2. semantic errors

Question 30

A method of locating a bug by gradually narrowing down its source using print statements.

Answer 30

describe the debugging method
Wolf Fencing

Question 31

give 3 examples of
syntax errors

Answer 31

examples of this include:
1. Wrong order of tokens: new ArrayList()<>;
2. Missing tokens: hello world"; or int x = 55
3. Mismatched tokens: int y = (10 / 2) * (3 + 4) + 6);

Question 32

Using known invalid inputs to check that the code responds appropriately.

Answer 32

describe
Negative Testing

Question 33

describe a
logical error

Answer 33

Result in incorrect behavior of the program due to incorrect implementation by the programmer.

Question 34

Result in incorrect behavior of the program due to incorrect implementation by the programmer.

Answer 34

describe a
logical error

Question 35

think of 5 points about
runtime errors

Answer 35

points include:
1. Occur during the execution of the bytecode
2. Can occur soon after execution or go unnoticed for years
3. Can be detected by JVM or programmer, but some may not signal their presence
4. Result from logical errors, misuse of library code, or failure to take into account software usage
5. May also occur due to reasons out of the programmer’s control such as deleted files, internet failure, JVM failure, or timing errors with the larger system.

Question 36

describe
ArithmeticException

Answer 36

created when an exceptional arithmetic condition has occurred

for example, when division by zero has occurred

Question 37

examples of this include:
1. incorrect if statement
2. assigning incorrect value to a variable
3. incorrect argument value
4. incorrect value returned from a method
5. incorrect expression calculation.

Answer 37

try and think of 5 examples of a
logical error

Question 38

try and think of 5 examples of a
logical error

Answer 38

examples of this include:
1. incorrect if statement
2. assigning incorrect value to a variable
3. incorrect argument value
4. incorrect value returned from a method
5. incorrect expression calculation.

Question 39

An error that is caused by violating higher-level relationships between parts of code, rather than incorrect syntax.

Answer 39

describe
Semantic Error

Question 40

describe
Design by Contract

Answer 40

A concept that requires programmers to follow a “contract” of only using valid arguments to prevent errors and unexpected behavior.

if the programmer does not comply then it is there fault for any errors

Question 41

What is a
Format Specifier
in formatting strings?

Answer 41

this is a string within a template string that defines rules of how it will be replaced by a variable.

Question 42

A process of going through a section of code line by line to understand how each line affects the state of the object or other parts of the application.

Answer 42

describe the debugging method
Manual Walkthrough

Question 43

examples of this include:
1. Unreachable statements: return x + y; y++;
2. Using an incompatible type of argument in a method call
3. Using an incompatible type of operand with an operator
4. Failing to initialize a local variable before it is first used.
5. Return types not defined correctly
6. Missing variables

Answer 43

think of 6 possible examples
semantic errors

Question 44

describe
Runtime errors

Answer 44

Errors that only become apparent when a program is run, and have not been detected beforehand.

theseerrors can be caused by logical errors or conditions outside of the control of the programmer.

Question 45

An error detected by acompilerwhen code iscompiled.

Nobytecode (.class)is generated if these are present.

Answer 45

decsribe
Compilation errors

Question 46

created when an exceptional arithmetic condition has occurred

for example, when division by zero has occurred

Answer 46

describe
ArithmeticException

Question 47

describe an
Off-by-One Error

Answer 47

A logical error in which code is off by one unit

example:
a comparison operator that checks “<” when “<=” was required

Question 48

created to indicate that a method that converts a string to one of the numeric types has been passed an argument with an inappropriate format

Answer 48

describe
NumberFormatException

Question 49

these include:
1. syntax errors
2. semantic errors

Answer 49

what are two common
compile time errors

Question 50

describe the debugging method
Wolf Fencing

Answer 50

A method of locating a bug by gradually narrowing down its source using print statements.

Question 51

which two
options are available in java to format strings

Answer 51

these include:
1. System.out.printf()
2. String.format()

Question 52

An approach that attempts to prevent errors and unexpected behavior through misuses.

Answer 52

describe
Defensive Code

Question 53

the rule for this is:
“the number and type of the format specifiers must match the argument values given”

Answer 53

what is the rule for when multiple format specifiers are used in a string template

Question 54

two approaches that prevent this are:
1. Design by Contract
2. Defensive Code

Answer 54

what are 2 approaches that try and
prevent the misuse of code by programmers

Question 55

describe
StringIndexOutOfBoundsException

Answer 55

created when a program tries to access a part of a string using an index outside the string’s limits

Question 56

examples of this include:
1. Wrong order of tokens: new ArrayList()<>;
2. Missing tokens: hello world"; or int x = 55
3. Mismatched tokens: int y = (10 / 2) * (3 + 4) + 6);

Answer 56

give 3 examples of
syntax errors

Question 57

describe
Negative Testing

Answer 57

Using known invalid inputs to check that the code responds appropriately.

Question 58

when performing this:
1. Consider printing hard copies of the code and walking away from the computer
2. Make notes about what each line of code is doing
3. Don’t delve into method calls until you’ve noted the current line of code

Answer 58

what 3 things should be kept in mind when performing a
manual walkthrough

Question 59

what is the rule for when multiple format specifiers are used in a string template

Answer 59

the rule for this is:
“the number and type of the format specifiers must match the argument values given”

Question 60

A logical error in which code is off by one unit

example:
a comparison operator that checks “<” when “<=” was required

Answer 60

describe an
Off-by-One Error

Question 61

Using known and valid inputs to check that code produces expected outputs.

Answer 61

describe
positive testing

Question 62

created when a program tries to access a part of a string using an index outside the string’s limits

Answer 62

describe
StringIndexOutOfBoundsException

Question 63

Testing with values at and near the extreme values of data fields and collection sizes.

can prevent an error known as an “off-by-one error”

Answer 63

describe
Boundary Testing

Question 64

describe the
“Cannot Find Symbol” Error

Answer 64

this is an error that occurs when a variable identifier is not found.

Question 65

this is an error that occurs when a variable identifier is not found.

Answer 65

describe the
“Cannot Find Symbol” Error

Question 66

describe
ArrayIndexOutOfBoundsException

Answer 66

created when a program tries to access an array with an index outside the array’s limits

Question 67

what 3 things should be kept in mind when performing a
manual walkthrough

Answer 67

when performing this:
1. Consider printing hard copies of the code and walking away from the computer
2. Make notes about what each line of code is doing
3. Don’t delve into method calls until you’ve noted the current line of code

Question 68

created when a program repeatedly calls methods until there is no stack space left to store the state of all the method invocations.

Answer 68

describe
StackOverflowError

Question 69

A concept that requires programmers to follow a “contract” of only using valid arguments to prevent errors and unexpected behavior.

if the programmer does not comply then it is there fault for any errors

Answer 69

describe
Design by Contract

Question 70

created when you try to call a method using a reference variable whose value isnull

Answer 70

describe
NullPointerException

Question 71

created when we try and access an index that is out of bounds such as on an ArrayList

Answer 71

describe
IndexOutOfBoundsException

Question 72

created when a program tries to access an array with an index outside the array’s limits

Answer 72

describe
ArrayIndexOutOfBoundsException

Question 73

describe
Defensive Code

Answer 73

An approach that attempts to prevent errors and unexpected behavior through misuses.