C Declare Function As Static
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Chapter 5 Names, Bindings, and Scopes
Chapter 5 Names, Bindings, and Scopes 5.1 Introduction 198 5.2 Names 199 5.3 Variables 200 5.4 The Concept of Binding 203 5.5 Scope 211 5.6 Scope and Lifetime 222 5.7 Referencing Environments 223 5.8 Named Constants 224 Summary • Review Questions • Problem Set • Programming Exercises 227 CMPS401 Class Notes (Chap05) Page 1 / 20 Dr. Kuo-pao Yang Chapter 5 Names, Bindings, and Scopes 5.1 Introduction 198 Imperative languages are abstractions of von Neumann architecture – Memory: stores both instructions and data – Processor: provides operations for modifying the contents of memory Variables are characterized by a collection of properties or attributes – The most important of which is type, a fundamental concept in programming languages – To design a type, must consider scope, lifetime, type checking, initialization, and type compatibility 5.2 Names 199 5.2.1 Design issues The following are the primary design issues for names: – Maximum length? – Are names case sensitive? – Are special words reserved words or keywords? 5.2.2 Name Forms A name is a string of characters used to identify some entity in a program. Length – If too short, they cannot be connotative – Language examples: . FORTRAN I: maximum 6 . COBOL: maximum 30 . C99: no limit but only the first 63 are significant; also, external names are limited to a maximum of 31 . C# and Java: no limit, and all characters are significant . C++: no limit, but implementers often impose a length limitation because they do not want the symbol table in which identifiers are stored during compilation to be too large and also to simplify the maintenance of that table. -
Java Programming Standards & Reference Guide
Java Programming Standards & Reference Guide Version 3.2 Office of Information & Technology Department of Veterans Affairs Java Programming Standards & Reference Guide, Version 3.2 REVISION HISTORY DATE VER. DESCRIPTION AUTHOR CONTRIBUTORS 10-26-15 3.2 Added Logging Sid Everhart JSC Standards , updated Vic Pezzolla checkstyle installation instructions and package name rules. 11-14-14 3.1 Added ground rules for Vic Pezzolla JSC enforcement 9-26-14 3.0 Document is continually Raymond JSC and several being edited for Steele OI&T noteworthy technical accuracy and / PD Subject Matter compliance to JSC Experts (SMEs) standards. 12-1-09 2.0 Document Updated Michael Huneycutt Sr 4-7-05 1.2 Document Updated Sachin Mai L Vo Sharma Lyn D Teague Rajesh Somannair Katherine Stark Niharika Goyal Ron Ruzbacki 3-4-05 1.0 Document Created Sachin Sharma i Java Programming Standards & Reference Guide, Version 3.2 ABSTRACT The VA Java Development Community has been establishing standards, capturing industry best practices, and applying the insight of experienced (and seasoned) VA developers to develop this “Java Programming Standards & Reference Guide”. The Java Standards Committee (JSC) team is encouraging the use of CheckStyle (in the Eclipse IDE environment) to quickly scan Java code, to locate Java programming standard errors, find inconsistencies, and generally help build program conformance. The benefits of writing quality Java code infused with consistent coding and documentation standards is critical to the efforts of the Department of Veterans Affairs (VA). This document stands for the quality, readability, consistency and maintainability of code development and it applies to all VA Java programmers (including contractors). -
Declaring Data Member Public C
Declaring Data Member Public C Rickard brooch stickily. Interceptive and hamulate Connie enure, but Norbert crossways extinguishes her patroness. Is Mario estimated or electrotonic when strangulating some moribundity deified deeply? Optimize for declaring data member public If dynamic allocation is necessary, prefer to keep ownership with the code that allocated it. This process of creating an object from a class is known as instantiation. Here is the quite surprising output of the program. Data attributes need not be declared; like local variables, they spring into existence when they are first assigned to. The term __________ means the ability to takemany forms. In many cases, this is not a problem, but it is a problem in some cases. Use rvalue references only in certain special cases listed below. By default, functions and data members of the class are public. How many data members should be in every class and why? Is it acceptable to omit default constructors in a class? For accessing the data, the declaration of a friend function should be done inside the body of a class starting with the keyword friend. The constructor is declared much like a normal member function but it will share the name of the class and it has no return value. Spirit would be impossible without it. The basic idea is really very simple. Giving sensible names to types and variables is much better than using obscure names that you must then explain through comments. Special member functions called constructors and destructors. This makes it impossible for the class to ensure that invariant properties of that variable are respected. -
Java Programming 2 – Lecture #1 – [email protected]
Java Programming 2 – Lecture #1 – [email protected] About the Java Programming Language Java is an object-oriented, high-level programming language. It is a platform-neutral language, with a ‘write once run anywhere’ philosophy. This is supported by a virtual machine architecture called the Java Virtual Machine (JVM). Java source programs are compiled to JVM bytecode class files, which are converted to native machine code on platform-specific JVM instances. .java source .class JVM executable code files Java bytecode files JVM machine code compiler runtime Java is currently one of the top programming languages, according to most popularity metrics.1 Since its introduction in the late 1990s, it has rapidly grown in importance due to its familiar programming syntax (C-like), good support for modularity, relatively safe features (e.g. garbage collection) and comprehensive library support. Our First Java Program It is traditional to write a ‘hello world’ program as a first step in a new language: /** * a first example program to print Hello world */ public class Hello { public static void main(String [] args) { System.out.println(“Hello world”); } } Contrast with Python Whereas Python programs are concise, Java programs appear verbose in comparison. Python has dynamic typing, but Java uses static typing. Python scripts are generally interpreted from source, whereas Java programs are compiled to bytecode then executed in a high-performance just-in-time native compiler. 1 E.g. see http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html Supporting User Input in Simple Java Programs There are two ways to receive text-based user input in simple programs like our ‘hello world’ example. -
Using the Java Bridge
Using the Java Bridge In the worlds of Mac OS X, Yellow Box for Windows, and WebObjects programming, there are two languages in common use: Java and Objective-C. This document describes the Java bridge, a technology from Apple that makes communication between these two languages possible. The first section, ÒIntroduction,Ó gives a brief overview of the bridgeÕs capabilities. For a technical overview of the bridge, see ÒHow the Bridge WorksÓ (page 2). To learn how to expose your Objective-C code to Java, see ÒWrapping Objective-C FrameworksÓ (page 9). If you want to write Java code that references Objective-C classes, see ÒUsing Java-Wrapped Objective-C ClassesÓ (page 6). If you are writing Objective-C code that references Java classes, read ÒUsing Java from Objective-CÓ (page 5). Introduction The original OpenStep system developed by NeXT Software contained a number of object-oriented frameworks written in the Objective-C language. Most developers who used these frameworks wrote their code in Objective-C. In recent years, the number of developers writing Java code has increased dramatically. For the benefit of these programmers, Apple Computer has provided Java APIs for these frameworks: Foundation Kit, AppKit, WebObjects, and Enterprise Objects. They were made possible by using techniques described later in Introduction 1 Using the Java Bridge this document. You can use these same techniques to expose your own Objective-C frameworks to Java code. Java and Objective-C are both object-oriented languages, and they have enough similarities that communication between the two is possible. However, there are some differences between the two languages that you need to be aware of in order to use the bridge effectively. -
Classes in C++
Classes in C++ Bryce Boe 2012/08/15 CS32, Summer 2012 B Overview • Finish Sor?ng recap • Thinking object oriented recap • Classes in C++ • Building a class in C++ (real ?me demo) Sor?ng recap • Bubble sort • Inser?on sort • Selec?on sort • Merge sort • Heapsort • Quicksort Thinking object oriented recap • Language as an influence of thought process • OO concepts – Separaon of interface and implementaon – Informaon hiding – Inheritance • Wri?ng reusable code Exci?ng Note for Today • The gcc compiler now requires C++ to build – Essen?ally means parts of the gcc compiler are wriVen in C++ • hp://gcc.gnu.org/git/? p=gcc.git;a=commit;h=2b15d2ba7eb3a25d]1 5a7300f4ee7a141ee8539 Structures • Structures provide a way to organize data • Structures in C++ are essen?ally classes, not true in C Classes • an object is a variable that has member func?ons (instance methods) • a class is a data type whose variables are objects • Class – Describe the kind of values the variables hold (state) – Describe the member func?ons (behavior) Terminology • The book uses member to mean a par?cular instance of a class • The book uses members to mean aributes of a class (variables and methods) • Funcon and method are somewhat used interchangeably • Similar: – member variable = instance variable – member method = instance method Classes • Provide encapsulaon – Combining a number of items, such as variables and func?ons, into a single package, such as an object of some class (or instance of the class) Scope Resolu?on Operator • ClassName::method_name • Used to iden?fy -
C Programming Tutorial
C Programming Tutorial C PROGRAMMING TUTORIAL Simply Easy Learning by tutorialspoint.com tutorialspoint.com i COPYRIGHT & DISCLAIMER NOTICE All the content and graphics on this tutorial are the property of tutorialspoint.com. Any content from tutorialspoint.com or this tutorial may not be redistributed or reproduced in any way, shape, or form without the written permission of tutorialspoint.com. Failure to do so is a violation of copyright laws. This tutorial may contain inaccuracies or errors and tutorialspoint provides no guarantee regarding the accuracy of the site or its contents including this tutorial. If you discover that the tutorialspoint.com site or this tutorial content contains some errors, please contact us at [email protected] ii Table of Contents C Language Overview .............................................................. 1 Facts about C ............................................................................................... 1 Why to use C ? ............................................................................................. 2 C Programs .................................................................................................. 2 C Environment Setup ............................................................... 3 Text Editor ................................................................................................... 3 The C Compiler ............................................................................................ 3 Installation on Unix/Linux ............................................................................ -
Software II: Principles of Programming Languages Introduction
Software II: Principles of Programming Languages Lecture 5 – Names, Bindings, and Scopes Introduction • Imperative languages are abstractions of von Neumann architecture – Memory – Processor • Variables are characterized by attributes – To design a type, must consider scope, lifetime, type checking, initialization, and type compatibility Names • Design issues for names: – Are names case sensitive? – Are special words reserved words or keywords? Names (continued) • Length – If too short, they cannot be connotative – Language examples: • FORTRAN 95: maximum of 31 (only 6 in FORTRAN IV) • C99: no limit but only the first 63 are significant; also, external names are limited to a maximum of 31 (only 8 are significant K&R C ) • C#, Ada, and Java: no limit, and all are significant • C++: no limit, but implementers often impose one Names (continued) • Special characters – PHP: all variable names must begin with dollar signs – Perl: all variable names begin with special characters, which specify the variable’s type – Ruby: variable names that begin with @ are instance variables; those that begin with @@ are class variables Names (continued) • Case sensitivity – Disadvantage: readability (names that look alike are different) • Names in the C-based languages are case sensitive • Names in others are not • Worse in C++, Java, and C# because predefined names are mixed case (e.g. IndexOutOfBoundsException ) Names (continued) • Special words – An aid to readability; used to delimit or separate statement clauses • A keyword is a word that is special only -
CS307: Principles of Programming Languages
CS307: Principles of Programming Languages LECTURE 12: NAMES, SCOPES, AND BINDINGS II LECTURE OUTLINE • INTRODUCTION • BINDINGS • LIFETIME AND STORAGE MANAGEMENT • SCOPE RULES • STATIC SCOPING • DYNAMIC SCOPING • STATIC VS DYNAMIC SCOPING • DEEP VS SHALLOW BINDING • POLYMORPHISM, DYNAMIC BINDING, GENERIC PROGRAMMING • METHOD MATCHING VS BINDING • BINDING OF REFERENCE ENVIRONMENTS • SEPARATE COMPILATION 2 CS307 : Principles of Programming Languages - (c) Paul Fodor (CS Stony Brook), Tony Mione (SUNY Korea) and Pearson SCOPE RULES • BINDING SCOPE IS THE TEXTUAL REGION OF THE PROGRAM IN WHICH A BINDING IS ACTIVE • A SCOPE IS A PROGRAM SECTION OF MAXIMAL SIZE WHERE • NO BINDINGS CHANGE • MINIMALLY: NO RE-DECLARATIONS ARE PERMITTED • SCOPING RULE EXAMPLE 1: DECLARATION BEFORE USE • CAN A NAME BE USED BEFORE IT IS DECLARED? • JAVA LOCAL VARS: NO • JAVA CLASS PROPERTIES AND METHODS: YES • THE SCOPE OF A BINDING IS DETERMINED STATICALLY OR DYNAMICALLY 3 CS307 : Principles of Programming Languages - (c) Paul Fodor (CS Stony Brook), Tony Mione (SUNY Korea) and Pearson SCOPING RULES • SCOPING RULE EXAMPLE 2: TWO USES OF A GIVEN NAME. DO THEY REFER TO THE SAME BINDING? a = 1 ... def f(): a = 2 b = a SCOPING RULES DETERMINE WHETHER OR NOT THIS IS THE CASE 4 CS307 : Principles of Programming Languages - (c) Paul Fodor (CS Stony Brook), Tony Mione (SUNY Korea) and Pearson SCOPE RULES • KEY IDEA: IN STATIC SCOPE RULES -> BINDINGS DEFINED BY THE PHYSICAL (LEXICAL) STRUCTURE OF THE PROGRAM • STATIC SCOPING (ALSO CALLED LEXICAL SCOPING) EXAMPLES: • ONE BIG -
Important Java Programming Concepts
Appendix A Important Java Programming Concepts This appendix provides a brief orientation through the concepts of object-oriented programming in Java that are critical for understanding the material in this book and that are not specifically introduced as part of the main content. It is not intended as a general Java programming primer, but rather as a refresher and orientation through the features of the language that play a major role in the design of software in Java. If necessary, this overview should be complemented by an introductory book on Java programming, or on the relevant sections in the Java Tutorial [10]. A.1 Variables and Types Variables store values. In Java, variables are typed and the type of the variable must be declared before the name of the variable. Java distinguishes between two major categories of types: primitive types and reference types. Primitive types are used to represent numbers and Boolean values. Variables of a primitive type store the actual data that represents the value. When the content of a variable of a primitive type is assigned to another variable, a copy of the data stored in the initial variable is created and stored in the destination variable. For example: int original = 10; int copy = original; In this case variable original of the primitive type int (short for “integer”) is assigned the integer literal value 10. In the second assignment, a copy of the value 10 is used to initialize the new variable copy. Reference types represent more complex arrangements of data as defined by classes (see Section A.2). -
About Classes 14.1 Instance and Static Members Tree Class
Ch 14: More About Classes 14.1 Instance and Static Members ! instance variable: a member variable in a class. Each object (instance) has its own copy. CS 2308 ! static variable: one variable shared among all Fall 2013 objects of a class Jill Seaman ! static member function: - can be used to access static member variable; ‣ normal functions can access static member variables, too - but it cannot access instance variables 1 - can be called before any objects are defined2 string name1 = “Steve Jobs”; string name1 = “Steve Jobs”; cout << “Name” << name1 << endl; cout << “Name” << name1 << endl; Tree class declaration Program demo of static variable // Tree class class Tree { private: Static member variable #include <iostream> static int objectCount; declared here using namespace std; public: #include "Tree.h" Tree(); int getObjectCount(); int main() { }; Tree oak; Tree elm; // Definition of the static member variable, written Tree pine; // outside the class. Static member variable int Tree::objectCount = 0; defined here (required) cout << “We have “ << pine.getObjectCount() // Member functions defined << “Trees in our program.\n”; Tree::Tree() { Static variable is incremented objectCount++; each time Tree is constructed. } } int Tree::getObjectCount() { return objectCount; What will be the output? } 3 4 string name1 = “Steve Jobs”; string name1 = “Steve Jobs”; cout << “Name” << name1 << endl; cout << “Name” << name1 << endl; Three Instances of the Tree Class, static member function But Only One objectCount Variable ! Declared with static -
More on Classes (Chapter 14.1, 14.3-14.5)
More on Classes (Chapter 14.1, 14.3-14.5) Dr. Yingwu Zhu 14.1 Instance and Static Members Instance and Static Members • instance variable: a member variable in a class. Each object has its own copy. • static variable: one variable shared among all objects of a class • static member function: can be used to access static member variable; can be called before any objects are defined 14-3 static member variable Contents of Tree.h 1 // Tree class 2 class Tree Static member declared here. 3 { 4 private: 5 static int objectCount; // Static member variable. 6 public: 7 // Constructor 8 Tree() 9 { objectCount++; } 10 11 // Accessor function for objectCount 12 int getObjectCount() const 13 { return objectCount; } 14 }; Static member defined here. 15 16 // Definition of the static member variable, written 17 // outside the class. 18 int Tree::objectCount = 0; 14-4 14-5 Three Instances of the Tree Class, But Only One objectCount Variable 14-6 static member function • Declared with static before return type: static int getObjectCount() const { return objectCount; } • Static member functions can only access static member data (Why ?) • Can be called independent of objects: int num = Tree::getObjectCount(); 14-7 Modified Version of Tree.h 1 // Tree class 2 class Tree 3 { 4 private: 5 static int objectCount; // Static member variable. 6 public: 7 // Constructor 8 Tree() 9 { objectCount++; } 10 11 // Accessor function for objectCount 12 static int getObjectCount() const 13 { return objectCount; } 14 }; 15 16 // Definition of the static member variable, written 17 // outside the class. 18 int Tree::objectCount = 0; Now we can call the function like this: cout << "There are " << Tree::getObjectCount() << " objects.\n"; 14-8 14.3 Memberwise Assignment Memberwise Assignment • Can use = to assign one object to another, or to initialize an object with an object’s data • Copies member to member.