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Arithmetic Operators
Arithmetic Operators Section 2.15 & 3.2 p 60-63, 81-89 9/9/10 CS150 Introduction to Computer Science 1 1 Today • Arithmetic Operators & Expressions o Computation o Precedence o Associativity o Algebra vs C++ o Exponents 9/9/10 CS150 Introduction to Computer Science 1 2 Assigning floats to ints int intVariable; intVariable = 42.7; cout << intVariable; • What do you think is the output? 9/9/10 CS150 Introduction to Computer Science 1 3 Assigning doubles to ints • What is the output here? int intVariable; double doubleVariable = 78.9; intVariable = doubleVariable; cout << intVariable; 9/9/10 CS150 Introduction to Computer Science 1 4 Arithmetic Expressions Arithmetic expressions manipulate numeric data We’ve already seen simple ones The main arithmetic operators are + addition - subtraction * multiplication / division % modulus 9/9/05 CS120 The Information Era 5 +, -, and * Addition, subtraction, and multiplication behave in C++ in the same way that they behave in algebra int num1, num2, num3, num4, sum, mul; num1 = 3; num2 = 5; num3 = 2; num4 = 6; sum = num1 + num2; mul = num3 * num4; 9/9/05 CS120 The Information Era 6 Division • What is the output? o int grade; grade = 100 / 20; cout << grade; o int grade; grade = 100 / 30; cout << grade; 9/9/10 CS150 Introduction to Computer Science 1 7 Division • grade = 100 / 40; o Check operands of / . the data type of grade is not considered, why? o We say the integer is truncated. • grade = 100.0 / 40; o What data type should grade be declared as? 9/9/10 CS150 Introduction to Computer Science 1 8 -
Chapter 7 Expressions and Assignment Statements
Chapter 7 Expressions and Assignment Statements Chapter 7 Topics Introduction Arithmetic Expressions Overloaded Operators Type Conversions Relational and Boolean Expressions Short-Circuit Evaluation Assignment Statements Mixed-Mode Assignment Chapter 7 Expressions and Assignment Statements Introduction Expressions are the fundamental means of specifying computations in a programming language. To understand expression evaluation, need to be familiar with the orders of operator and operand evaluation. Essence of imperative languages is dominant role of assignment statements. Arithmetic Expressions Their evaluation was one of the motivations for the development of the first programming languages. Most of the characteristics of arithmetic expressions in programming languages were inherited from conventions that had evolved in math. Arithmetic expressions consist of operators, operands, parentheses, and function calls. The operators can be unary, or binary. C-based languages include a ternary operator, which has three operands (conditional expression). The purpose of an arithmetic expression is to specify an arithmetic computation. An implementation of such a computation must cause two actions: o Fetching the operands from memory o Executing the arithmetic operations on those operands. Design issues for arithmetic expressions: 1. What are the operator precedence rules? 2. What are the operator associativity rules? 3. What is the order of operand evaluation? 4. Are there restrictions on operand evaluation side effects? 5. Does the language allow user-defined operator overloading? 6. What mode mixing is allowed in expressions? Operator Evaluation Order 1. Precedence The operator precedence rules for expression evaluation define the order in which “adjacent” operators of different precedence levels are evaluated (“adjacent” means they are separated by at most one operand). -
Lexical Analysis with Flex Edition 2.5.35, 8 February 2013
Lexical Analysis with Flex Edition 2.5.35, 8 February 2013 Vern Paxson, Will Estes and John Millaway The flex manual is placed under the same licensing conditions as the rest of flex: Copyright c 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2012 The Flex Project. Copyright c 1990, 1997 The Regents of the University of California. All rights reserved. This code is derived from software contributed to Berkeley by Vern Paxson. The United States Government has rights in this work pursuant to contract no. DE- AC03-76SF00098 between the United States Department of Energy and the University of California. Redistribution and use in source and binary forms, with or without modification, are per- mitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of con- ditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED “AS IS” AND WITHOUT ANY EXPRESS OR IM- PLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WAR- RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. i Table of Contents 1 Copyright ................................. 1 2 Reporting Bugs............................ 2 3 Introduction ............................... 3 4 Some Simple Examples..................... 4 5 Format of the Input File ................... 6 5.1 Format of the Definitions Section ............................ -
Parsing Arithmetic Expressions Outline
Parsing Arithmetic Expressions https://courses.missouristate.edu/anthonyclark/333/ Outline Topics and Learning Objectives • Learn about parsing arithmetic expressions • Learn how to handle associativity with a grammar • Learn how to handle precedence with a grammar Assessments • ANTLR grammar for math Parsing Expressions There are a variety of special purpose algorithms to make this task more efficient: • The shunting yard algorithm https://eli.thegreenplace.net/2010/01/02 • Precedence climbing /top-down-operator-precedence-parsing • Pratt parsing For this class we are just going to use recursive descent • Simpler • Same as the rest of our parser Grammar for Expressions Needs to account for operator associativity • Also known as fixity • Determines how you apply operators of the same precedence • Operators can be left-associative or right-associative Needs to account for operator precedence • Precedence is a concept that you know from mathematics • Think PEMDAS • Apply higher precedence operators first Associativity By convention 7 + 3 + 1 is equivalent to (7 + 3) + 1, 7 - 3 - 1 is equivalent to (7 - 3) – 1, and 12 / 3 * 4 is equivalent to (12 / 3) * 4 • If we treated 7 - 3 - 1 as 7 - (3 - 1) the result would be 5 instead of the 3. • Another way to state this convention is associativity Associativity Addition, subtraction, multiplication, and division are left-associative - What does this mean? You have: 1 - 2 - 3 - 3 • operators (+, -, *, /, etc.) and • operands (numbers, ids, etc.) 1 2 • Left-associativity: if an operand has operators -
CALI Round 03.Pdf
California Academic Learning Initiative 2015 - 2016 Round 3 Written by Ankit Aggarwal, Hidehiro Anto, P.C. Chauhan, Jason Cheng, Boyang Jiao, Aseem Keyal, Eddie Kim, Bruce Lou, Charlie Mann, Kevin Wang, Corry Wang, Kion You TOSSUPS 1. T he Supreme Court has decided that tailored use of this practice is permissible for achieving so-called "critical mass," although Sandra Day O'Connor wrote that this practice would no longer be necessary in 25 years. In 2003 the Supreme Court ruled against a point-based version of this practice in G ratz v. Bollinger. In June 2015 the court agreed to rehear the case (*) Fisher v. Texas challenging this practice. In 1978 quota-based versions of this practice were ruled unconstitutional in B akke v. Regents of the University of California . For 10 points, name this practice of giving preference to historically disadvantaged racial minorities. ANSWER: affirmative action in the college admissions process [accept positive discrimination; prompt on "reverse discrimination" or "discrimination"] 2. A leader criticized this religion's contradictions in his essay Against the Galileans during the 4th century. According to legend, one of this religion's major holidays was specifically scheduled to upstage a festival led by the Sol Invictus cult. Julian the Apostate attempted to roll back the spread of this religion, whose members were systematically persecuted by (*) D iocletian ( "DIE"-oh-klee-shun). It was granted toleration in the Edict of Milan by Constantine the Great, who became the first Roman emperor to convert to it. For 10 points, Pontius Pilate crucified the founder of what religion? ANSWER: Christianity [accept specific forms of Christianity] 3. -
Operators Precedence and Associativity This Page Lists All C Operators in Order of Their Precedence (Highest to Lowest)
Operators Precedence and Associativity This page lists all C operators in order of their precedence (highest to lowest). Operators within the same box have equal precedence. Precedence Operator Description Associativity () Parentheses (grouping) left-to-right [] Brackets (array subscript) 1 . Member selection via object name -> Member selection via pointer ++ -- Postfix increment/decrement (see Note 1) ++ -- Prefix increment/decrement right-to-left + - Unary plus/minus ! ~ Logical negation/bitwise complement 2 (type) Cast (change type) * Dereference & Address sizeof Determine size in bytes 3 */% Multiplication/division/modulus left-to-right 4 + - Addition/subtraction left-to-right 5 << >> Bitwise shift left, Bitwise shift right left-to-right 6 < <= Relational less than/less than or equal to left-to-right > >= Relational greater than/greater than or equal to 7 == != Relational is equal to/is not equal to left-to-right 8 & Bitwise AND left-to-right 9 ^ Bitwise exclusive OR left-to-right 10 | Bitwise inclusive OR left-to-right 11 && Logical AND left-to-right 12 || Logical OR left-to-right 13 ?: Ternary conditional right-to-left = Assignment right-to-left += -= Addition/subtraction assignment 14 *= /= Multiplication/division assignment %= &= Modulus/bitwise AND assignment ^= |= Bitwise exclusive/inclusive OR assignment <<= >>= Bitwise shift left/right assignment 15 , Comma (separate expressions) left-to-right Note 1 - Postfix increment/decrement have high precedence, but the actual increment or decrement of the operand is delayed (to be accomplished sometime before the statement completes execution). So in the statement y = x * z++; the current value of z is used to evaluate the expression (i.e., z++ evaluates to z) and z only incremented after all else is done. -
Expressions and Assignment Statements Operator Precedence
Chapter 6 - Expressions and Operator Precedence Assignment Statements • A unary operator has one operand • Their evaluation was one of the motivations for • A binary operator has two operands the development of the first PLs • A ternary operator has three operands • Arithmetic expressions consist of operators, operands, parentheses, and function calls The operator precedence rules for expression evaluation define the order in which “adjacent” Design issues for arithmetic expressions: operators of different precedence levels are 1. What are the operator precedence rules? evaluated 2. What are the operator associativity rules? – “adjacent” means they are separated by at 3. What is the order of operand evaluation? most one operand 4. Are there restrictions on operand evaluation side effects? Typical precedence levels: 5. Does the language allow user-defined operator 1. parentheses overloading? 2. unary operators 6. What mode mixing is allowed in expressions? 3. ** (if the language supports it) 4. *, / 5. +, - Chapter 6 Programming 1 Chapter 6 Programming 2 Languages Languages Operator Associativity Operand Evaluation Order The operator associativity rules for expression The process: evaluation define the order in which adjacent 1. Variables: just fetch the value operators with the same precedence level are evaluated 2. Constants: sometimes a fetch from memory; sometimes the constant is in the machine Typical associativity rules: language instruction • Left to right, except **, which is right to left • Sometimes unary operators associate -
Software II: Principles of Programming Languages Why Expressions?
Software II: Principles of Programming Languages Lecture 7 – Expressions and Assignment Statements Why Expressions? • Expressions are the fundamental means of specifying computations in a programming language • To understand expression evaluation, need to be familiar with the orders of operator and operand evaluation • Essence of imperative languages is dominant role of assignment statements 1 Arithmetic Expressions • Arithmetic evaluation was one of the motivations for the development of the first programming languages • Arithmetic expressions consist of operators, operands, parentheses, and function calls Arithmetic Expressions: Design Issues • Design issues for arithmetic expressions – Operator precedence rules? – Operator associativity rules? – Order of operand evaluation? – Operand evaluation side effects? – Operator overloading? – Type mixing in expressions? 2 Arithmetic Expressions: Operators • A unary operator has one operand • A binary operator has two operands • A ternary operator has three operands Arithmetic Expressions: Operator Precedence Rules • The operator precedence rules for expression evaluation define the order in which “adjacent” operators of different precedence levels are evaluated • Typical precedence levels – parentheses – unary operators – ** (if the language supports it) – *, / – +, - 3 Arithmetic Expressions: Operator Associativity Rule • The operator associativity rules for expression evaluation define the order in which adjacent operators with the same precedence level are evaluated • Typical associativity -
C Programming and Data Structures May/June 2007
C Programming and Data Structures May/June 2007 SET-2 1. (a) What is a string constant? How do string constants differ from character constants? Do string constants represent numerical values? A string constant is a sequence of characters enclosed in double quotes. The characters may be letters, numbers, special characters and blank spaces. Example: hai , 1982, etc; A character constant is not equivalent to the single character constant. A single character string constant does not have an equivalent integer whereas a character constant has an integer value (ASCII value). String constants do not represent equivalent numerical values. (b) Summarize the standard escape sequences in C. Describe them. Black slash characters are also called escape sequences. Constant Meaning \a Audible alert(bell) \b Back space \f Form feed \n New line \r Carriage return \t Tab space \v Vertical tab \ Single quote \ Double quote \? Question mark \\ Back slash \0 Null (c) What is a variable? How can variables be characterized? Give the rules for variable declaration. A variable is a data name that may be used to store a data value. A variable may take different values at different times during execution. Variables are characterized based on the value they hold. Depending on that they are classified into int, float, char, double, and so on. Rules for variable declaration: · They must begin with a letter. Some compilers permit underscore as the first character. · ANSI standard recognizes a length of 31 characters. However, the length should not be normally more than eight characters. Appendix-C.p65 12 7/29/08, 5:21 PM Solved Question Papers C.13 · Uppercase and lowercase are significant. -
Arithmetic Expressions
Chapter 7 Expressions and Assignment Statements (updated edition 11) ISBN 0-321-49362-1 Chapter 7 Topics • Introduction • Arithmetic Expressions • Overloaded Operators • Type Conversions • Relational and Boolean Expressions • Short-Circuit Evaluation • Assignment Statements • Mixed-Mode Assignment 2 Introduction • Expressions are the fundamental means of specifying computations in a programming language • To understand expression evaluation, need to be familiar with the orders of operator and operand evaluation • Essence of imperative languages is dominant role of assignment statements 3 Arithmetic Expressions • Arithmetic evaluation was one of the motivations for the development of the first programming languages • Arithmetic expressions consist of operators, operands, parentheses, and function calls 4 Arithmetic Expressions: Design Issues • Design issues for arithmetic expressions – Operator precedence rules? – Operator associativity rules? – Order of operand evaluation? – Operand evaluation side effects? – Operator overloading? – Type mixing in expressions? 5 Arithmetic Expressions: Operators • A unary operator has one operand • A binary operator has two operands • A ternary operator has three operands 6 Arithmetic Expressions: Operator Precedence Rules • The operator precedence rules for expression evaluation define the order in which “adjacent” operators of different precedence levels are evaluated • Typical precedence levels – parentheses – unary operators – ** (if the language supports it) – *, / – +, - 7 Arithmetic Expressions: Operator -
Introduction to Programming with C-19CSE23 Module 1
Introduction to programming with C-19CSE23 Module 1 Hardware Components Processor, memoryand Input/Output devices, are the important components of adigital computer. Processor will have ALU (Arithmetic Logic Unit) and Control Unit(CU) as its components. Memory can be subdivided into primary and secondary memory. Input devices accept data and control signals from the user. Examples of input devices are keyboard, mouse, pen based systems, data scanners, game controllers, voice recognition systems etc. Output devices communicate the processed data to the user. Examples of output devices are Monitor, Printer, Plotter, sound system etc. Processor Central Processing Unit (CPU) -It is the brain of the computer. It performs the bulk ofthe data processing operations. The function of the processor is to fetch the instructionfrom memory, examine (decode) the instruction and execute the instructions. It consists of Control unit, Arithmetic Logic Unit (ALU) and registers. Control unit is responsible for fetching the instructions from memory and interpreting them. ALU performs arithmetic and logical operations. Registers are very high speed memory unitsfor storing very small amount of data. Program counter, Instruction register, Memoryaddress register, memory buffer register and accumulator are some examples of registers.Bus is a collection of wires. They may be unidirectional or bidirectional. Bus is usedto connect different parts of a computer. Bus may be serial or parallel. USB is anexample of a serial bus. Bus connecting computer and a dot matrix printer is normallya parallel bus. Parallel bus carries several bits at a time. These bits may indicateinstruction, data, address or commands. Bus width and Bus speed are the two major components for performance measure of a computer. -
Rsyslog Doc Documentation Release 8.26.0
Rsyslog Doc Documentation Release 8.26.0 foo bar Aug 24, 2017 Contents 1 Manual 3 2 Reference 301 3 Sponsors and Community 343 4 Related Links 345 i ii Rsyslog Doc Documentation, Release 8.26.0 Rsyslog is a rocket-fast system for log processing. It offers high-performance, great security features and a modular design. While it started as a regular syslogd, rsyslog has evolved into a kind of swiss army knife of logging, being able to • accept inputs from a wide variety of sources, • transform them, • and output the results to diverse destinations. Rsyslog has a strong enterprise focus but also scales down to small systems. It supports, among others, MySQL, Post- greSQL, failover log destinations, ElasticSearch, syslog/tcp transport, fine grain output format control, high precision timestamps, queued operations and the ability to filter on any message part. Contents 1 Rsyslog Doc Documentation, Release 8.26.0 2 Contents CHAPTER 1 Manual Configuration Rsyslogd is configured via the rsyslog.conf file, typically found in /etc. By default, rsyslogd reads the file /etc/ rsyslog.conf. This can be changed by a command line option. Note that configurations can be built interactively via the online rsyslog configuration builder tool. Basic Structure This section describes how rsyslog configuration basically works. Think of rsyslog as a big logging and event pro- cessing toolset. It can be considered a framework with some basic processing that is fixed in the way data flows, but is highly customizable in the details of this message flow. During configuration, this customization is done by defining and customizing the rsyslog objects.