Fill in the blanks in each of the following: a) Each class declaration that begins with keyword ______ must be stored in a file that has exactly the same name as the class and ends with the . java file-name extension. b) Keyword ______ in a class declaration is followed immediately by the class's name. c) Keyword ______ requests memory from the system to store an object, then calls the corresponding class's constructor to initialize the object. d) Each parameter must specify both a(n) ______ and \(a(n)\) ______ e) By default, classes that are compiled in the same directory are considered to be in the same package, known as the ______ . f) When each object of a class maintains its own copy of an attribute, the field that represents the attribute is also known as a(n) ______ g) Java provides two primitive types for storing floating-point numbers in memory: ______ and ______ h) Variables of type double represent ______ floating-point numbers. i) Scanner method ______ returns a double value. j) Keyword public is an access ______ k) Return rype ______ indicates that a method will not return a value. I) scanner method ______ reads characters until it encounters a newline character,then returns those characters as a String. \(\mathrm{m}\) ) Class \(\operatorname{Str}\) ing is in package ______ n) \(A(n)\) ______ is not required if you always refer to a class with its fully qualified class name. o) \(A(n)\) ______ is a number with a decimal point, such as 7.33,0.0975 or 1000.12345 p) Variables of type \(f\) loat represent______ floating-point numbers. q) The format specifier ______ is used to output values of type float or double. r) Types in Java are divided into two categories ______ types and ______ types.

Step by step solution

01

- Class Declaration Keyword

To find the keyword that every class declaration that must be stored in a file with the same name, we look into Java's rules for class declarations. The keyword that must always match the file name for a public class is 'public'. Hence, the blank should be filled with the keyword 'public'.

02

- Keyword Followed by Class Name

After specifying the access level of a class with a keyword, the syntax of Java requires that this keyword be followed directly by the class’s name. The keyword here is 'class'.

03

- Keyword for Creating Objects

The keyword that requests memory from the system to store an object and calls the class constructor is 'new'.

04

- Component of a Parameter

Each parameter in a method declaration must specify a type that tells us what kind of values it can hold, and a name which is a variable to store the corresponding value. The blank should be filled with 'type' and 'name'.

05

- Default Package Name

By default, if no package declaration is specified, Java classes are considered to be part of a special unnamed package, often referred to as the default package.

06

- Field Representing an Attribute

When an object has its own copy of an attribute it's referred to as an instance variable or instance field.

07

- Floating-Point Types

Java has two primitive types for floating-point numbers: 'float' and 'double'.

08

- Double Precision

Variables of type double represent double-precision floating-point numbers.

09

- Scanner Method for Double

The Scanner method that returns a double value is 'nextDouble()'.

10

- Access Specifier Keyword

The keyword 'public' is an access specifier. It specifies the visibility of classes, methods, and variables.

11

- Return Type for No Value

The return type 'void' indicates that a method will not return any value.

12

- Scanner Method for String

The Scanner method that reads characters until it encounters a newline character and returns those characters as a String, is 'nextLine()'.

13

- Package for Class String

The class String is part of the 'java.lang' package.

14

- Requirement for Import Statements

An import statement is not required if a class is always referred to with its fully qualified name, which includes the package name.

15

- Term for Decimal Numbers

A number with a decimal point, such as 7.33, 0.0975, or 1000.12345, is called a floating-point number.

16

- Float Precision

Variables of type float represent single-precision floating-point numbers.

17

- Format Specifier for Floats and Doubles

The format specifier for outputting values of type float or double is '%f'.

18

- Categories of Types in Java

Types in Java are divided into two categories: primitive types and reference types.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Java Syntax

Understanding Java syntax is akin to learning the grammar rules that govern a language; it dictates how code should be written to be correctly understood and executed by the Java Virtual Machine (JVM). Starting with class declarations, Java requires naming a class file with the exact name of the public class it contains, followed by the .java extension. This aligns with Java's strong convention on code readability and maintenance.

In a class declaration, after the access specifier, such as 'public', the keyword 'class' is used to signify the start of a class declaration. Subsequent to this, the class name is provided, which is a user-defined identifier adhering to Java's naming conventions. Inside the class body—demarcated by curly braces ({ })—members such as variables and methods are declared, each with its specified type and name. For example, in a method declaration, each parameter must have a type, indicating the kind of values it will store, and a name, which will be utilized inside the method for various operations.

Moreover, in discussions about class-level members, visibility is a key topic. The 'public' access specifier allows a class or member to be accessible from anywhere in the application. Conversely, there are other access specifiers (like private and protected) that restrict access in various ways to promote encapsulation.

Object-Oriented Programming

Object-oriented programming (OOP) is a paradigm centered on 'objects'—instances of classes that represent a combination of data and behaviors. Java, being an object-oriented language, provides the flexibility to create modular, reusable, and extensible code. Objects are instantiated using the keyword 'new', which allocates memory and invokes the constructor of a class to initialize the object.

In the realm of OOP, the concept of 'instance variables' becomes important. These are the attributes belonging to each instance of the class that maintain their own unique state. They are also known as instance fields, as each object has its own copy, distinct from those of other instances of the same class.

The OOP in Java also underscores the packaging of classes. Classes compiled in the same directory and not explicitly declared in a named package belong to a default unnamed package. However, using named packages is beneficial in organizing code logically and avoiding name conflicts. Additionally, OOP introduces the idea of fully qualified names, where using the complete package and class name could eliminate the need for import statements but at the cost of brevity in the code.

Java Primitive Data Types

Java categorizes types into primitive and reference types, reflecting the language's simplicity and flexibility. Java primitive data types are predefined by the language and serve as the basic building blocks for data manipulation. These are not objects and hold their values directly in the memory where they are declared.

Among the primitive types are the 'float' and 'double', both deal with floating-point numbers. The 'float' represents single-precision (32-bit) floating-point numbers, useful for applications that do not require a very high degree of precision and wish to save on memory. On the other hand, 'double' variables use double precision (64-bit), offering more accuracy and are used when high precision in calculation is a must.

It is because of this distinction that Java has separate format specifiers in the System.out.printf method—'%f' can be used to format both 'float' and 'double' types. When it comes to real numbers in programs, such as 7.33 or 1000.12345, they are typically processed as 'double' precision unless specified otherwise. Thus, understanding the distinction between primitive data types is crucial for efficient memory management and precise calculations in Java programming.