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Java编程入门复习速查表（一级）是针对加拿大计算机科学专业CST8116“计算机编程导论”课程的期末复习资料，旨在帮助初学者掌握基础的Java编程概念。以下是一些关键知识点的详细解释： 1. **Joyce Farell开发周期**： - **理解问题**：明确需求，理解程序需要解决的具体问题。 - **规划逻辑**：设计程序的工作流程和结构。 - **编写代码**：将规划转化为具体的编程语言。 - **翻译代码**：可能是指将伪代码或流程图转化为实际的编程语句。 - **测试程序**：验证程序功能是否正确，寻找并修复错误。 - **投入生产**：将程序部署到实际环境，供用户使用。 - **维护程序**：持续监控和更新，确保程序的稳定性和适应性。 2. **Cay Horstmann开发过程**： - **理解问题**：与Joyce Farell相同。 - **开发并描述算法**：详细描述解决问题的步骤。 - **测试算法**：用简单输入检查算法的正确性。 - **翻译算法**：将算法转化为代码。 - **编译和测试程序**：验证代码无误并运行测试。 3. **算法**： - 算法是解决问题的一系列有序步骤，有明确的起点和终点。在计算机程序中，算法就是一系列指令。 4. **规划工具**： - **伪代码**：一种介于自然语言和编程语言之间的表述方式，用于描述算法。 - **流程图**：图形化表示程序的执行流程，直观易懂。 - **UML类图**：面向对象编程中的设计工具，描绘对象之间的关系和交互。 5. **编程范式**： - **命令式编程**：如Java，程序员需明确指定数据处理方式，强调如何执行操作。 - **声明式编程**：如SQL，只描述所需结果，由编译器决定执行方式。 6. **API文档**： - **模块和包**：模块是组织包的机制，包则是组织类的机制，如Java的标准库有`java.lang`（自动导入）和`java.util`（需显式导入）等。 7. **方法**： - 方法是将大段处理步骤分解为可复用的单元，类似于函数。与变量不同，方法存储的是操作而非数据。 - **方法重载**：在同一类中，两个方法名字相同但参数列表不同（类型或数量），编译器根据传入参数决定调用哪个方法。 8. **工作方法**： - 类内部的方法，用于实现类的功能。例如，类中的getter和setter方法，用于获取和设置对象的属性。这些基础知识构成了Java编程的基础，对于初学者来说是必不可少的。理解并掌握这些概念，将有助于构建坚实的编程基础，并为进一步学习更复杂的Java特性打下坚实基础。在复习过程中，除了理论知识，还要注重实践，通过编写代码来加深理解，这样才能更好地应对期末考试。

Joyce Farell development cycle: 1) Understand the problem; 2) Plan the logic; 3) Write the code; 4) Translate the code; 7) Test the program; 8) Put the program into production; 7)

Maintain the program.

Cay Horstmann development process: 1) Understand the problem; 2) Develop and describe an algorithm; 3) Test

algorithm with simple inputs; 4) Translate algorithm; 5) Compile and test the program.

Algorithm: A solution to a problem, as a sequence of steps initiated with one starting point, and finishing at one exit

point. Computer programs are algorithms, and each step is referred to as a statement.

Pseudocode and Flowcharts: Use to plan an algorithm. UML class diagrams: blueprints for objects which are used by

programmers who are using an OOP language.

Imperative programmers: OPP and PP are imperative because they are required to detail how the program will

process data to get to the result. Declarative programmers: SQL is declarative because it requests the software to

provide a result and the software determines how to get the result.

API documentation (Modules and Packages): Modules are ways to organize packages, and packages are a way to organize classes. Java. Lang

(imported automatically) classes are used in all Java programs like String. Java. Util (imported explicitly) classes that provide miscellaneous

utilities like Scanner.

Methods: a way to break large sequences of processing steps, into smaller, re-usable units (functional decomposition). Unlike variables, which are

a named place (named as a thing [noun]) in the computer’s memory that stores a value, a method is a named place (named as an action [verb]) in

the computer’s memory that contains processing steps. Calling methods can be documented like an external method call. Method overloading:

occurs when two methods have the same name, but different signatures (type and the number of parameters). The compiler uses the parameters

to determine which method to use. Work methods: Methods inside a class that perform calculations or provide a service. Modularization: allows

abstraction (a method name represents processing, making it easier to program at a higher level), the ability of multiple programmers to work on different parts of a program at the

same time, and code reuse. Its only drawback is overhead: modules use more resources (memory, processing) than just coding steps.

Parameters: The data types and variable names are defined as part of the method definition (where data can be provided to the method). Arguments: Data passed to a parameter

within the parameters list.

Class: a class is a blueprint for an Object. We use a class to construct objects in the computer’s memory. Object: An object is an allocation of memory that contains properties (data

stored in attributes) and behaviors (methods that perform processing on the data inside the object). Through objects, we can break a problem’s solution into many smaller parts.

The public methods of a class are collectively referred to as its public interface. Constructors: a method used to instantiate an object based on the class definition. They require the

“new” operator to work. The “new” operator does not return the object, it returns a reference to the object in memory. Typically, constructors are overloaded. The public methods

of a class are collectively referred to as the public interface of the class.

Accessors: A method that returns a value held in an object and that does not change the state of the object. Mutator: A method that does not return a value but modifies the state

of the object.

Variables: [modifiers][data type][identifier][assignment operator(=)][initial value]. A variable identifier must start with a letter or underscore character. Special characters or the

$ symbol are not allowed. The assignment operator is right-associative. Before we can use a variable, we must initialize it. This can be done on the same line or on different lines.

Constant: A constant is a variable that has been constrained so that once a value is set, it cannot be changed. Constants in Java are declared by adding the keyword ‘final’ in front of

the data type.

Static class: Static members belong to a class and they are used at the class level, not at the object level. The keyword static is used

to indicate that a variable is part of the class. Utility methods that do not use any of the instance variables can also be labeled as

static (like the main method). Statics variables are allocated into memory once and each object instantiated from the class shares a

copy of the static member in memory. The Java Virtual Machine performs a lot of work when we use a static class member. We can

use a static member in an instance member, but we cannot use an instance member inside a static member.

Reference types VS primitive types: A Primitive type stores the value directly in the memory the variable represents. Primitive

types are stored in separate memory locations, independent of each other. Reference type stores a reference-to-an-object in

memory, but it does not store the object itself. The memory location assigned to a reference type doesn’t store its actual value, it

stores a reference to the position (address) in memory where the value of the object is located.

Scanner: private Scanner scanner = new Scanner (System.in); next() will read in text

data until it encounters any whitespace character, then it will return the next data up to

the whitespace. nextLine() will read in all the data until it encounters a line terminator

character (enter key). Use nextLine () when asking a user to enter the full name on one

line. nextLine () is not good when asking a user to enter numbers and text one after the

other. nextInt () and nextDouble ()stop, when they encounter an enter key character in

the input but don’t remove it. nextLine () reads in data and exits immediately when it

sees \n, if nextInt() or nextDouble() were used first, nextLine see’s the removes the

, and returns an empty String. The result is the program skips an entry and the user cannot type anything in. The fix is to call nextLine () immediately after any call to nextInt() or

nextDouble().

Unified Modeling Language: a UML Class diagram is a type of UML diagram that represents a design for a class and is not language specific. They can also include the data types

and go after each identifier: .

Instance variables: are declared at the class level, and exist in memory while the instance exists in memory.

Access modifiers: We cannot use the access modifiers inside a method, local scope variables, including parameters are implicitly private to that method.

This keyword: When the program is running, ‘this’ is made to reference an object from the inside. There are two uses for this: 1) To call another constructor internally. 2) To resolve

the scope, between instance variables at the class level, and local-scope variables at the method level that have the same name. Scope: The visibility of a variable, depends on

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