Topic 8.5: Handling Exceptions - Recognize common exception classes (such as NullPointerException, ArithmeticException, ArrayIndexOutOfBoundsException, ClassCastException)

Question 1

What are the common causes of a FileNotFoundException?

Answer 1

Common causes include providing an incorrect file path or attempting to access a file that is not accessible.

Question 2

This is thrown when an invalid string format is encountered during parsing or conversion to a numeric type.

Answer 2

What is a NumberFormatException?

Question 3

How can you handle a NullPointerException?

Answer 3

To handle this, check if the reference is null before accessing it to avoid the exception. Alternatively, catch the exception and handle it appropriately.

Question 4

This can occur in scenarios such as:

Performing calculations like 5 / 0 or 10 % 0.

Answer 4

Provide an example scenario where an ArithmeticException can occur.

Question 5

This is thrown when an attempt is made to cast an object to a type that is not compatible with its actual runtime type.

Answer 5

What is a ClassCastException?

Question 6

What are the common causes of a RuntimeException?

Answer 6

some common causes are:

Various unexpected runtime conditions, such as division by zero, null references, and out-of-bounds array access.

Question 7

What are the common causes of an IllegalArgumentException?

Answer 7

Common causes of this include passing invalid or unexpected values as arguments to a method.

Question 8

Common causes include providing an incorrect file path or attempting to access a file that is not accessible.

Answer 8

What are the common causes of a FileNotFoundException?

Question 9

This is thrown when an arithmetic operation encounters an exceptional condition, such as division by zero.

Answer 9

What is an ArithmeticException?

Question 10

What is a RuntimeException?

Answer 10

This is a superclass of several common unchecked exceptions, including ArithmeticException, NullPointerException, and ArrayIndexOutOfBoundsException.

It represents various runtime errors that can occur during program execution.

Question 11

Common causes of this include passing invalid or unexpected values as arguments to a method.

Answer 11

What are the common causes of an IllegalArgumentException?

Question 12

Common causes include parsing a string that does not represent a valid numeric value.

Answer 12

What are the common causes of a NumberFormatException?

Question 13

Causes of this include: Various input/output-related errors, such as failure to read or write data, network connectivity issues, etc.

Answer 13

What are the common causes of an IOException?

Question 14

What are the common causes of a StringIndexOutOfBoundsException?

Answer 14

common causes include trying to access a character at an index that is either negative or exceeds the length of the string.

Question 15

To handle this, check if the reference is null before accessing it to avoid the exception. Alternatively, catch the exception and handle it appropriately.

Answer 15

How can you handle a NullPointerException?

Question 16

This is a general exception class for input/output operations and represents various types of exceptional conditions related to file and network operations.

Answer 16

What is an IOException?

Question 17

What is an IndexOutOfBoundsException?

Answer 17

This is a superclass of ArrayIndexOutOfBoundsException and StringIndexOutOfBoundsException

it is thrown when attempting to access an invalid index within a collection, such as an array, vector, string, and so forth.

It can also be implemented within custom classes to indicate invalid access was attempted for a collection1.

Question 18

What are the common causes of a NumberFormatException?

Answer 18

Common causes include parsing a string that does not represent a valid numeric value.

Question 19

What is a NullPointerException?

Answer 19

This is thrown when a program tries to access or invoke a method on a null reference.

Question 20

Example scenario:

Opening a non-existent file using new FileInputStream("nonexistent.txt").

Answer 20

Provide an example scenario where a FileNotFoundException can occur.

Question 21

How can you handle an ArithmeticException?

Answer 21

To handle this ensure that the denominator in division or modulus operations is non-zero. Alternatively, catch the exception and handle it appropriately.

Question 22

This is thrown when an invalid index is used to access an array element.

Answer 22

What is an ArrayIndexOutOfBoundsException?

Question 23

Common causes of this include trying to access an element at an index that is outside the acceptable range of the array.

Answer 23

What are the common causes of an ArrayIndexOutOfBoundsException?

Question 24

This is typically thrown when a method receives an illegal or inappropriate argument.

Answer 24

What is an IllegalArgumentException?

Question 25

Provide an example scenario where a FileNotFoundException can occur.

Answer 25

Example scenario:

Opening a non-existent file using new FileInputStream("nonexistent.txt").

Question 26

This is thrown when an attempt is made to access a character in a string using an index that is either negative or greater than or equal to the length of the string.

Answer 26

What is a StringIndexOutOfBoundsException?

Question 27

What is a FileNotFoundException?

Answer 27

This is thrown when an attempt is made to access a file that does not exist or cannot be opened.

Question 28

How can you handle a StringIndexOutOfBoundsException?

Answer 28

Ensure that the index used to access the string is within the valid range. Alternatively, catch the exception and handle it appropriately.

Question 29

What is a ClassCastException?

Answer 29

This is thrown when an attempt is made to cast an object to a type that is not compatible with its actual runtime type.

Question 30

This is a superclass of several common unchecked exceptions, including ArithmeticException, NullPointerException, and ArrayIndexOutOfBoundsException.

It represents various runtime errors that can occur during program execution.

Answer 30

What is a RuntimeException?

Question 31

What is an ArithmeticException?

Answer 31

This is thrown when an arithmetic operation encounters an exceptional condition, such as division by zero.

Question 32

What are the common causes of an IOException?

Answer 32

Causes of this include: Various input/output-related errors, such as failure to read or write data, network connectivity issues, etc.

Question 33

What is a StringIndexOutOfBoundsException?

Answer 33

This is thrown when an attempt is made to access a character in a string using an index that is either negative or greater than or equal to the length of the string.

Question 34

To hanlde this ensure that the index used to access the array is within the valid range. Alternatively, catch the exception and handle it appropriately.

Answer 34

How can you handle an ArrayIndexOutOfBoundsException?

Question 35

How can you handle a FileNotFoundException?

Answer 35

To handle this ensure that the file exists and is accessible before attempting to access it. Alternatively, catch the exception and handle it appropriately.

Question 36

How can you handle a ClassCastException?

Answer 36

To handle this use the instanceof operator to check the object’s type before performing the cast to ensure compatibility. Alternatively, catch the exception and handle it appropriately.

Question 37

example scenarios include calling:

Integer.parseInt("abc")

or

Double.parseDouble("12.34.56")

Answer 37

Provide an example scenario where a NumberFormatException can occur.

Question 38

What are the common causes of a ClassCastException?

Answer 38

Common causes of this are trying to cast an object to an incompatible type in cases where there is no inheritance or interface relationship between the types.

Question 39

This is thrown when an attempt is made to access a file that does not exist or cannot be opened.

Answer 39

What is a FileNotFoundException?

Question 40

What is an IOException?

Answer 40

This is a general exception class for input/output operations and represents various types of exceptional conditions related to file and network operations.

Question 41

Ensure that the index used to access the string is within the valid range. Alternatively, catch the exception and handle it appropriately.

Answer 41

How can you handle a StringIndexOutOfBoundsException?

Question 42

Provide an example scenario where an ArrayIndexOutOfBoundsException can occur.

Answer 42

Example scenarios of this are:

Accessing array[5] when the array length is 5 or accessing a negative index like array[-1].

Question 43

common causes include trying to access a character at an index that is either negative or exceeds the length of the string.

Answer 43

What are the common causes of a StringIndexOutOfBoundsException?

Question 44

Common causes include:

Division or modulus operations where the divisor is zero.

Answer 44

What are the common causes of an ArithmeticException?

Question 45

What are the common causes of an ArithmeticException?

Answer 45

Common causes include:

Division or modulus operations where the divisor is zero.

Question 46

Common causes of this are trying to cast an object to an incompatible type in cases where there is no inheritance or interface relationship between the types.

Answer 46

What are the common causes of a ClassCastException?

Question 47

Example scenarios of this are:

Accessing array[5] when the array length is 5 or accessing a negative index like array[-1].

Answer 47

Provide an example scenario where an ArrayIndexOutOfBoundsException can occur.

Question 48

To handle this ensure that the file exists and is accessible before attempting to access it. Alternatively, catch the exception and handle it appropriately.

Answer 48

How can you handle a FileNotFoundException?

Question 49

How can you handle an IllegalArgumentException?

Answer 49

To handle this validate the input values before passing them to a method. Alternatively, catch the exception and handle it appropriately.

Question 50

What are the common causes of a NullPointerException?

Answer 50

common cuases of this are trying to call a method or access a field on an object that has not been initialized or is null.

Question 51

Provide an example scenario where a StringIndexOutOfBoundsException can occur.

Answer 51

example scenarios include:

Calling string.charAt(-1) or string.charAt(string.length()).

Question 52

common cuases of this are trying to call a method or access a field on an object that has not been initialized or is null.

Answer 52

What are the common causes of a NullPointerException?

Question 53

Provide an example scenario where a NumberFormatException can occur.

Answer 53

example scenarios include calling:

Integer.parseInt("abc")

or

Double.parseDouble("12.34.56")

Question 54

What are the common causes of an ArrayIndexOutOfBoundsException?

Answer 54

Common causes of this include trying to access an element at an index that is outside the acceptable range of the array.

Question 55

To handle this validate the string format before parsing it to a numeric type using methods such as regex. Alternatively, catch the exception and handle it appropriately.

Answer 55

How can you handle a NumberFormatException?

Question 56

To handle this use the instanceof operator to check the object’s type before performing the cast to ensure compatibility. Alternatively, catch the exception and handle it appropriately.

Answer 56

How can you handle a ClassCastException?

Question 57

example scenarios include:

Calling string.charAt(-1) or string.charAt(string.length()).

Answer 57

Provide an example scenario where a StringIndexOutOfBoundsException can occur.

Question 58

What is an ArrayIndexOutOfBoundsException?

Answer 58

This is thrown when an invalid index is used to access an array element.

Question 59

To handle this validate the input values before passing them to a method. Alternatively, catch the exception and handle it appropriately.

Answer 59

How can you handle an IllegalArgumentException?

Question 60

What is a NumberFormatException?

Answer 60

This is thrown when an invalid string format is encountered during parsing or conversion to a numeric type.

Question 61

How can you handle an ArrayIndexOutOfBoundsException?

Answer 61

To hanlde this ensure that the index used to access the array is within the valid range. Alternatively, catch the exception and handle it appropriately.

Question 62

some common causes are:

Various unexpected runtime conditions, such as division by zero, null references, and out-of-bounds array access.

Answer 62

What are the common causes of a RuntimeException?

Question 63

To handle this ensure that the denominator in division or modulus operations is non-zero. Alternatively, catch the exception and handle it appropriately.

Answer 63

How can you handle an ArithmeticException?

Question 64

How can you handle a NumberFormatException?

Answer 64

To handle this validate the string format before parsing it to a numeric type using methods such as regex. Alternatively, catch the exception and handle it appropriately.

Question 65

This is a superclass of ArrayIndexOutOfBoundsException and StringIndexOutOfBoundsException

it is thrown when attempting to access an invalid index within a collection, such as an array, vector, string, and so forth.

It can also be implemented within custom classes to indicate invalid access was attempted for a collection1.

Answer 65

What is an IndexOutOfBoundsException?

Question 66

Provide an example scenario where an ArithmeticException can occur.

Answer 66

This can occur in scenarios such as:

Performing calculations like 5 / 0 or 10 % 0.

Question 67

This is thrown when a program tries to access or invoke a method on a null reference.

Answer 67

What is a NullPointerException?

Question 68

What is an IllegalArgumentException?

Answer 68

This is typically thrown when a method receives an illegal or inappropriate argument.