Java Compound Assignment Operators
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Chapter 2 Core Basics
Chapter 2 Core Basics In this chapter we introduce some of the basic concepts that are important for understanding what is to follow. We also introduce a few of the fundamental operations that are involved in the vast majority of useful programs. 2.1 Literals and Types Section 1.3 introduced the string literal. A string literal is a collection of characters enclosed in quotes. In general, a literal is code that exactly represents a value. In addition to a string literal, there are numeric literals. There are actually a few different types of numeric values in Python. There are integer values which correspond to whole numbers (i.e., the countable numbers that lack a fractional part). In Python, an integer is known as an int. A number that can have a fractional part is called a float (a float corresponds to a real number). For example, 42 is an int while 3.14 is a float. The presence of the decimal point makes a number a float—it doesn’t matter if the fractional part is zero. For example, the literal 3.0, or even just 3., are also floats1 despite the fact that these numbers have fractional parts of zero.2 There are some important differences between how computers work with ints and floats. For example, ints are stored exactly in the computer while, in general, floats are only stored approximately. This is a consequence of the fact that we are entering numbers as decimal numbers, i.e., numbers in the base 10 counting system, but the computer stores these numbers internally as a finite number of binary (base 2) digits. -
Lecture 3: Its Time to See the C
Computer Science 61C Spring 2017 Friedland and Weaver Lecture 3: Its time to see the C... 1 Agenda Computer Science 61C Spring 2017 Friedland and Weaver • Computer Organization • Compile vs. Interpret • C vs Java 2 ENIAC (U.Penn., 1946) First Electronic General-Purpose Computer Computer Science 61C Spring 2017 Friedland and Weaver • Blazingly fast (multiply in 2.8ms!) • 10 decimal digits x 10 decimal digits • But needed 2-3 days to setup new program, as programmed with patch cords and switches • At that time & before, "computer" mostly referred to people who did calculations 3 EDSAC (Cambridge, 1949) First General Stored-Program Computer Computer Science 61C Spring 2017 Friedland and Weaver • Programs held as numbers in memory • This is the revolution: It isn't just programmable, but the program is just the same type of data that the computer computes on • 35-bit binary 2’s complement words 4 Components of a Computer Computer Science 61C Spring 2017 Friedland and Weaver Memory Processor Input Enable? Read/Write Control Program Datapath Address PC Bytes Write Registers Data Arithmetic & Logic Unit Read Data Output (ALU) Data Processor-Memory Interface I/O-Memory Interfaces 5 Great Idea: Levels of Representation/Interpretation Computer Science 61C Spring 2017 Friedland and Weaver temp = v[k]; High Level Language v[k] = v[k+1]; We are here! Program (e.g., C) v[k+1] = temp; lw $t0, 0($2) Compiler Anything can be represented lw $t1, 4($2) Assembly Language as a number, sw $t1, 0($2) Program (e.g., MIPS) i.e., data or instructions sw $t0, 4($2) -
THE MEANING of “EQUALS” Charles Darr Take a Look at the Following Mathematics Problem
PROFESSIONAL DEVELOPMENT THE MEANING OF “EQUALS” Charles Darr Take a look at the following mathematics problem. has been explored by mathematics education researchers internationally (Falkner, Levi and Carpenter, 1999; Kieran, 1981, 1992; MacGregor Write the number in the square below that you think and Stacey, 1997; Saenz-Ludlow and Walgamuth, 1998; Stacey and best completes the equation. MacGregor, 1999; Wright, 1999). However, the fact that so many students appear to have this 4 + 5 = + 3 misconception highlights some important considerations that we, as mathematics educators, can learn from and begin to address. How difficult do you consider this equation to be? At what age do you In what follows I look at two of these considerations. I then go on to think a student should be able to complete it correctly? discuss some strategies we can employ in the classroom to help our I recently presented this problem to over 300 Year 7 and 8 students at students gain a richer sense of what the equals sign represents. a large intermediate school. More than half answered it incorrectly.1 Moreover, the vast majority of the students who wrote something other The meaning of “equals” than 6 were inclined to write the missing number as “9”. Firstly, it is worth considering what the equals sign means in a This result is not just an intermediate school phenomenon, however. mathematical sense, and why so many children seem to struggle to Smaller numbers of students in other Years were also tested. In Years 4, develop this understanding. 5 and 6, even larger percentages wrote incorrect responses, while at Years From a mathematical point of view, the equals sign is not a command 9 and 10, more than 20 percent of the students were still not writing a to do something. -
It's the Symbol You Put Before the Answer
It’s the symbol you put before the answer Laura Swithinbank discovers that pupils often ‘see’ things differently “It’s the symbol you put before the answer.” 3. A focus on both representing and solving a problem rather than on merely solving it; ave you ever heard a pupil say this in response to being asked what the equals sign is? Having 4. A focus on both numbers and letters, rather than H heard this on more than one occasion in my on numbers alone (…) school, I carried out a brief investigation with 161 pupils, 5. A refocusing of the meaning of the equals sign. Year 3 to Year 6, in order to find out more about the way (Kieran, 2004:140-141) pupils interpret the equals sign. The response above was common however, what really interested me was the Whilst reflecting on the Kieran summary, some elements variety of other answers I received. Essentially, it was immediately struck a chord with me with regard to my own clear that pupils did not have a consistent understanding school context, particularly the concept of ‘refocusing the of the equals sign across the school. This finding spurred meaning of the equals sign’. The investigation I carried me on to consider how I presented the equals sign to my out clearly echoed points raised by Kieran. For example, pupils, and to deliberate on the following questions: when asked to explain the meaning of the ‘=’ sign, pupils at my school offered a wide range of answers including: • How can we define the equals sign? ‘the symbol you put before the answer’; ‘the total of the • What are the key issues and misconceptions with number’; ‘the amount’; ‘altogether’; ‘makes’; and ‘you regard to the equals sign in primary mathematics? reveal the answer after you’ve done the maths question’. -
Operations Per Se, to See If the Proposed Chi Is Indeed Fruitful
DOCUMENT RESUME ED 204 124 SE 035 176 AUTHOR Weaver, J. F. TTTLE "Addition," "Subtraction" and Mathematical Operations. 7NSTITOTION. Wisconsin Univ., Madison. Research and Development Center for Individualized Schooling. SPONS AGENCY Neional Inst. 1pf Education (ED), Washington. D.C. REPORT NO WIOCIS-PP-79-7 PUB DATE Nov 79 GRANT OS-NIE-G-91-0009 NOTE 98p.: Report from the Mathematics Work Group. Paper prepared for the'Seminar on the Initial Learning of Addition and' Subtraction. Skills (Racine, WI, November 26-29, 1979). Contains occasional light and broken type. Not available in hard copy due to copyright restrictions.. EDPS PRICE MF01 Plum Postage. PC Not Available from EDRS. DEseR.TPT00S *Addition: Behavioral Obiectives: Cognitive Oblectives: Cognitive Processes: *Elementary School Mathematics: Elementary Secondary Education: Learning Theories: Mathematical Concepts: Mathematics Curriculum: *Mathematics Education: *Mathematics Instruction: Number Concepts: *Subtraction: Teaching Methods IDENTIFIERS *Mathematics Education ResearCh: *Number 4 Operations ABSTRACT This-report opens by asking how operations in general, and addition and subtraction in particular, ante characterized for 'elementary school students, and examines the "standard" Instruction of these topics through secondary. schooling. Some common errors and/or "sloppiness" in the typical textbook presentations are noted, and suggestions are made that these probleks could lend to pupil difficulties in understanding mathematics. The ambiguity of interpretation .of number sentences of the VW's "a+b=c". and "a-b=c" leads into a comparison of the familiar use of binary operations with a unary-operator interpretation of such sentences. The second half of this document focuses on points of vier that promote .varying approaches to the development of mathematical skills and abilities within young children. -
Perl II Operators, Truth, Control Structures, Functions, and Processing the Command Line
Perl II Operators, truth, control structures, functions, and processing the command line Dave Messina v3 2012 1 Math 1 + 2 = 3 # kindergarten x = 1 + 2 # algebra my $x = 1 + 2; # Perl What are the differences between the algebra version and the Perl version? 2 Math my $x = 5; my $y = 2; my $z = $x + $y; 3 Math my $sum = $x + $y; my $difference = $x - $y; my $product = $x * $y; my $quotient = $x / $y; my $remainder = $x % $y; 4 Math my $x = 5; my $y = 2; my $sum = $x + $y; my $product = $x - $y; Variable names are arbitrary. Pick good ones! 5 What are these called? my $sum = $x + $y; my $difference = $x - $y; my $product = $x * $y; my $quotient = $x / $y; my $remainder = $x % $y; 6 Numeric operators Operator Meaning + add 2 numbers - subtract left number from right number * multiply 2 numbers / divide left number from right number % divide left from right and take remainder take left number to the power ** of the right number 7 Numeric comparison operators Operator Meaning < Is left number smaller than right number? > Is left number bigger than right number? <= Is left number smaller or equal to right? >= Is left number bigger or equal to right? == Is left number equal to right number? != Is left number not equal to right number? Why == ? 8 Comparison operators are yes or no questions or, put another way, true or false questions True or false: > Is left number larger than right number? 2 > 1 # true 1 > 3 # false 9 Comparison operators are true or false questions 5 > 3 -1 <= 4 5 == 5 7 != 4 10 What is truth? 0 the number 0 is false "0" -
Unicode Compression: Does Size Really Matter? TR CS-2002-11
Unicode Compression: Does Size Really Matter? TR CS-2002-11 Steve Atkin IBM Globalization Center of Competency International Business Machines Austin, Texas USA 78758 [email protected] Ryan Stansifer Department of Computer Sciences Florida Institute of Technology Melbourne, Florida USA 32901 [email protected] July 2003 Abstract The Unicode standard provides several algorithms, techniques, and strategies for assigning, transmitting, and compressing Unicode characters. These techniques allow Unicode data to be represented in a concise format in several contexts. In this paper we examine several techniques and strategies for compressing Unicode data using the programs gzip and bzip. Unicode compression algorithms known as SCSU and BOCU are also examined. As far as size is concerned, algorithms designed specifically for Unicode may not be necessary. 1 Introduction Characters these days are more than one 8-bit byte. Hence, many are concerned about the space text files use, even in an age of cheap storage. Will storing and transmitting Unicode [18] take a lot more space? In this paper we ask how compression affects Unicode and how Unicode affects compression. 1 Unicode is used to encode natural-language text as opposed to programs or binary data. Just what is natural-language text? The question seems simple, yet there are complications. In the information age we are accustomed to discretization of all kinds: music with, for instance, MP3; and pictures with, for instance, JPG. Also, a vast amount of text is stored and transmitted digitally. Yet discretizing text is not generally considered much of a problem. This may be because the En- glish language, western society, and computer technology all evolved relatively smoothly together. -
Unary Operator
Introduction to Python Operations and Variables 1 Topics 1) Arithmetic Operations 2) Floor Division vs True Division 3) Modulo Operator 4) Operator Precedence 5) String Concatenation 6) Augmented Assignment 2 Arithmetic Operations 3 Mixing Types Any expression that two floats produce a float. x = 17.0 – 10.0 print(x) # 7.0 When an expression’s operands are an int and a float, Python automatically converts the int to a float. x = 17.0 – 10 print(x) # 7.0 y = 17 – 10.0 print(y) # 7.0 4 True Division vs Floor Division The operator / is true division and the operator // returns floor division(round down after true divide). True divide / always gives the answer as a float. print(23 // 7) # 3 print(3 // 9) # 0 print(-4 // 3) # -2 print(6 / 5) # 1.2 print(6 / 3) # 2.0 NOT 2! 5 Remainder with % The % operator computes the remainder after floor division. • 14 % 4 is 2 • 218 % 5 is 3 3 43 4 ) 14 5 ) 218 12 20 2 18 15 3 Applications of % operator: • Obtain last digit of a number: 230857 % 10 is 7 • Obtain last 4 digits: 658236489 % 10000 is 6489 • See whether a number is odd: 7 % 2 is 1, 42 % 2 is 0 6 Modulo Operator The operator % returns the modulus which is the remainder after floor division. print(18 % 5) # 3 print(2 % 9) # 2, if first number is smaller, it's the answer print(125 % 10) # 5 print(0 % 10) # 0 print(10 % 0) # ZeroDivisionError 7 Why floor/modulo division is useful Floor division allows us to extract the integer part of the division while the modulo operator extracts the remainder part of the division. -
Hyperoperations and Nopt Structures
Hyperoperations and Nopt Structures Alister Wilson Abstract (Beta version) The concept of formal power towers by analogy to formal power series is introduced. Bracketing patterns for combining hyperoperations are pictured. Nopt structures are introduced by reference to Nept structures. Briefly speaking, Nept structures are a notation that help picturing the seed(m)-Ackermann number sequence by reference to exponential function and multitudinous nestings thereof. A systematic structure is observed and described. Keywords: Large numbers, formal power towers, Nopt structures. 1 Contents i Acknowledgements 3 ii List of Figures and Tables 3 I Introduction 4 II Philosophical Considerations 5 III Bracketing patterns and hyperoperations 8 3.1 Some Examples 8 3.2 Top-down versus bottom-up 9 3.3 Bracketing patterns and binary operations 10 3.4 Bracketing patterns with exponentiation and tetration 12 3.5 Bracketing and 4 consecutive hyperoperations 15 3.6 A quick look at the start of the Grzegorczyk hierarchy 17 3.7 Reconsidering top-down and bottom-up 18 IV Nopt Structures 20 4.1 Introduction to Nept and Nopt structures 20 4.2 Defining Nopts from Nepts 21 4.3 Seed Values: “n” and “theta ) n” 24 4.4 A method for generating Nopt structures 25 4.5 Magnitude inequalities inside Nopt structures 32 V Applying Nopt Structures 33 5.1 The gi-sequence and g-subscript towers 33 5.2 Nopt structures and Conway chained arrows 35 VI Glossary 39 VII Further Reading and Weblinks 42 2 i Acknowledgements I’d like to express my gratitude to Wikipedia for supplying an enormous range of high quality mathematics articles. -
Programming Basics
Readings and References • Reading » Fluency with Information Technology Programming Basics • Chapter 18, Fundamental Concepts Expressed in JavaScript • Other References INFO/CSE 100, Autumn 2004 » Games and Puzzles Fluency in Information Technology • Thomas Jefferson National Accelerator Facility, Office of Science Education http://www.cs.washington.edu/100 • http://education.jlab.org/indexpages/elementgames.html 25-Oct-2004 cse100-11-programming © 2004 University of Washington 1 25-Oct-2004 cse100-11-programming © 2004 University of Washington 2 The Plan Begin with HTML • We will learn JavaScript over the next few Basic HTML is static lectures the contents of the file are displayed as given • JavaScript is used with HTML in Web pages <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" • JavaScript is a contemporary programming language -- "http://www.w3.org/TR/html4/loose.dtd"> we will learn only its basics <html> <head> • You will program in a text editor and run your program <title>Simple A</title> </head> with your browser <body> What is 2.0 + 2.0? </body> </html> JavaScript is a way to make HTML “dynamic” 25-Oct-2004 cse100-11-programming © 2004 University of Washington 3 25-Oct-2004 cse100-11-programming © 2004 University of Washington 4 Add some “dynamic” content JavaScript in an HTML page Scripting languages let us create active pages » implement actions to be taken at run-time when the page is <script> block loaded or in response to user event in <head> <head> <title>Simple B</title> Language we are javascript <head> -
UEB Guidelines for Technical Material
Guidelines for Technical Material Unified English Braille Guidelines for Technical Material This version updated October 2008 ii Last updated October 2008 iii About this Document This document has been produced by the Maths Focus Group, a subgroup of the UEB Rules Committee within the International Council on English Braille (ICEB). At the ICEB General Assembly in April 2008 it was agreed that the document should be released for use internationally, and that feedback should be gathered with a view to a producing a new edition prior to the 2012 General Assembly. The purpose of this document is to give transcribers enough information and examples to produce Maths, Science and Computer notation in Unified English Braille. This document is available in the following file formats: pdf, doc or brf. These files can be sourced through the ICEB representatives on your local Braille Authorities. Please send feedback on this document to ICEB, again through the Braille Authority in your own country. Last updated October 2008 iv Guidelines for Technical Material 1 General Principles..............................................................................................1 1.1 Spacing .......................................................................................................1 1.2 Underlying rules for numbers and letters.....................................................2 1.3 Print Symbols ..............................................................................................3 1.4 Format.........................................................................................................3 -
Using Regex to Parse Attribute-Value Pairs in a Macro Variable Rowland Hale, Syneos Health
PharmaSUG 2021 - Paper QT-134 Using Regex to Parse Attribute-Value Pairs in a Macro Variable Rowland Hale, Syneos Health ABSTRACT In some circumstances it may be deemed preferable to pass multiple values to a macro not via multiple parameters but via a list of attribute-value pairs in a single parameter. Parsing more complex parameter values such as these may seem daunting at first, but regular expressions help us make light of the task! This paper explains how to use the PRXPARSE, PRXMATCH and the lesser known PRXPOSN regular expression functions in SAS® to extract in robust fashion the values we need from such a list. The paper is aimed at those who wish to expand on a basic knowledge of regular expressions, and although the functions are applied and explained within a specific practical context, the knowledge gained will have much potential for wider use in your daily programming work. INTRODUCTION The author occasionally comes across seasoned and capable SAS programmers who haven’t taken the plunge into the powerful world of regular expressions. Not so surprising, given that regular expressions look, well, downright scary, don’t they? For sure, regex patterns can appear complex, but, on the other hand, when you see a series of three (or more!) “normal” (i.e. non regex) string handling functions, all mind-bogglingly nested on a single line of code (and, if in a macro context, each further buried inside a %SYSFUNC macro function) and realise that this can all be replaced with a relatively simple regular expression, you may start to wonder which is the easier to deal with.