3.1 Fundamentals Of Programming

Question 1

Name the two data types.

Answer 1

Primitive & Non-Primitive.

Question 2

What do Primitive data types include?

Answer 2

• Byte.
• Short.
• Int.
• Long.
• Float.
• Double.
• Boolean.
• Char.

Question 3

What do Non-Primitive data types include?

Answer 3

• String.
• Arrays.
• Classes.

Question 4

How many Primitive data types are there in Java?

Answer 4

Eight.

Question 5

Define a Byte data type.

Answer 5

Stores whole numbers from -128 to 127.

Question 6

Define the size of a byte data type.

Answer 6

1 Byte (8 bits).

Question 7

Define a Short data type.

Answer 7

Stores whole numbers from -32,768 to 32,767.

Question 8

Define the size of a Short data type.

Answer 8

2 Bytes (16 bits)

Question 9

Define an Int data type.

Answer 9

Stores whole numbers from -2,147,483,648 to 2,147,483,647.

Question 10

Define the size of an Int data type.

Answer 10

4 Bytes (32 bits).

Question 11

Define a Long data type.

Answer 11

Stores whole numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

Question 12

Define the size of a Long data type.

Answer 12

8 Bytes (64 bits).

Question 13

Define the data type Float.

Answer 13

Stores fractional numbers. Sufficient for storing six to seven decimal digits.

Question 14

Define the size of the Float data type.

Answer 14

4 Bytes (32 bits).

Question 15

Define a Boolean.

Answer 15

Stores true or false values.

Question 16

Define the size of a Boolean.

Answer 16

1 Bit.

Question 17

Define a char.

Answer 17

Stores a single character/letter or ASCII values.

Question 18

Define the size of a char.

Answer 18

2 Bytes (16 bits).

Question 19

Define the two primitive number groups.

Answer 19

Integer types & Floating Point types.

Question 20

Define the purpose of Integer types.

Answer 20

Store whole numbers, positive or negative, without decimals.

Question 21

Define the valid Integer Types.

Answer 21

• Byte.
• Short.
• Int.
• Long.

Which type you should use depends on the numeric value.

Question 22

Define a Double data type.

Answer 22

Stores fractional numbers. Sufficient for storing 15 decimal digits.

Question 23

Define the size of a Double.

Answer 23

8 Bytes (64 bits).

Question 24

Define the purpose of Floating Point Types.

Answer 24

Represent numbers with a fractional part, containing one or more decimals.

Question 25

Define the valid Floating Point Types.

Answer 25

• Float.

- Double.

Question 26

Define the difference between Float and Double.

Answer 26

The precision of a floating point value indicates how many digits the value can have after the decimal point. Whereas the precision of float is only about six or seven digits, double variables have a precision of 15 digits. Therefore, it is safer to use double for most calculations.

Question 27

Define a Non-Primitive data Type.

Answer 27

A data type that refers to an object. This is why they are also called reference types.

Question 28

Define the difference between a primitive and non-primitive data type.

Answer 28

Primitive types are predefined in Java, whereas non primitive types are defined by the user within Java.

Non primitive data types can be used to call methods to perform certain operations whereas primitive types can not.

A primitive type must always have a value, whereas non primitives can be defined as null.

Primitive types can be defined at the start with a lowercase letter, whereas non primitives begin with an uppercase letter.

The size of a primitive type depends on the data type, whereas non primitives have all the same size.

Question 29

Define a record.

Answer 29

A data structure that groups together related items of data.

Question 30

Define how a record differs from an array.

Answer 30

Records are more complex than arrays as you can store more than one type of data together.

Question 31

Define the Java.time package class ‘LocalDate’.

Answer 31

Represents a date (year, month, day (yyyy-MM-dd)).

Question 32

Define the Java.time package class ‘LocalTime’.

Answer 32

Represents a time (hour, minute, second and nanoseconds (HH-mm-ss-ns)).

Question 33

Define the Java.time package class ‘LocalDateTime’.

Answer 33

Represents both a date and a time (yyyy-MM-dd-HH-mm-ss-ns).

Question 34

Define the Java.time package class ‘DateTimeFormatter’.

Answer 34

Formatter for displaying and parsing date-time objects.

Question 35

What method is used to display the current Date?

Answer 35

‘.now( );’
e.g.
LocalDate myObj = LocalDate.now();

Question 36

What method is used to display the current Time?

Answer 36

‘.now ( );
e.g.
LocalTime myObj = LocalTime.now()

Question 37

What method is used to display the current Date and Time?

Answer 37

‘.now ( );
e.g.
LocalDateTime myObj = LocalDateTime.now()

Question 38

Define the purpose of ‘ofPattern ( )’.

Answer 38

Accepts all forms of values, if you want to display the date and time in a different format.

Question 39

Define an array.

Answer 39

An array is used to store multiple values in a single single variable, instead of declaring separate variables for each value.

Question 40

What is the syntax to declare an array?

Answer 40

Define the variable type with square brackets.

e.g.

int[] myNum = {10, 20, 30, 40);

Question 41

Define a multidimensional array

Answer 41

An array containing one or more arrays.

Question 42

Define the syntax for a multidimensional array.

Answer 42

Add each array within its own set of curly braces.

e.g.

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };

Question 43

How to access the elements of a two dimensional array

Answer 43

Specify two indexes: One for the array one one for the element inside that array.

e.g.

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
int x = myNumbers[1][2];