Welcome to CS 1342 Programming Concepts C++ Syllabus Review
• Syllabus: https://erikgabrielsen.com/courses/ cs1342spring2020
• Labs start week of 1/27 • CS Help Desk available (will be posting schedule on website)
• Make sure you join Slack! Why Computer Science
• CS is now the most popular major at Stanford, MIT, Princeton, Duke, UC San Diego, Tufts, and many more
• In 2020, there will be more than 1 million open jobs for CS Majors
• In 2020, there will be less than 50,000 graduates to fill those positions
• CS is currently the highest paid entry level job in America • Avg Starting Salary: $66,000 Week 1 Assignments
• Join the course Slack Due Wednesday
• Post a short bio in your sections slack channel. See my post for an example.
• Upload a profile picture so we know who you are!
• Homework 1 - ZyBook Chapter 1 and 2 Due Next Friday
• LabQuiz 1 Due Jan. 31st Chapter 1 Introduction to C++ C++ History and Overview
• C++ is a statically typed, general-purpose programming language that supports Object Oriented Programming and memory control / manipulation
• 4th Most Popular Programming Language (IEEE 2016) • Considered a “Middle Level” Language • C++ interacts directly with hardware of the computer History of C++
• C - Developed in 1978 by Brian Kernighan and Dennis Ritchie at AT&T Bell Labs.
• C was named after a language called B (short for BCPL) • C++ - Developed in 1985 by Bjarne Stroustrup • C++ added support for Object Oriented Programming • A Brief History of C++: https://s2.smu.edu/~devans/2341/ A%20Brief%20History%20of%20C.htm Major Versions of C++
• C++98 - Released in 1998 and released the STL (Standard Template Library) • C++11 - Released in 2011. Added improvements to the STL including many BOOST Libraries
• C++14 - Released 2014 - Introduction of polymorphic lambdas, digit separators, generalized lambda capture, variable templates, binary integer literals, quoted strings etc.
• C++17 - Released 2017 - Introduction of fold expressions, hexadecimal floating point literals, a u8 character literal, selection statements with initializer, inline variables etc.
• C++20 - Upcoming Release in 2020. Will include Concepts, Coroutines, and many other features.
In this class we will focus mostly on C++98 and C++11 features. Who uses C++
• Operating Systems (Mobile and Computer)
• Embedded Systems
• Drivers
• Browsers
• Gaming
• Cloud Computing • Timeline of Programming Languages: https:// en.wikipedia.org/wiki/Timelineofprogramming_languages Java vs C++
• Both Statically typed • Portability • Java uses the JVM • C++ compiles directly to byte code • Memory Management • Java - JVM manages memory • C++ - user must manage memory Java vs C++
• In C++, the basic unit of code is the function
• In Java, everything is a class
C++ Java
#include
using namespace std; public static void main(String[] args) { System.out.println("Hello, World"); int main() { } cout << "Hello World!" << endl; } return 0; }
examples: helloWorld.cpp helloWorld.java Introduction to C++ Programming, I/O and Operators Programming Basics
• Every C++ program starts in main()
• Each statement is followed with a semicolon
• main() returns 0
• A non-zero return notifies the operating system that something went wrong Example 1.1
#include
// code goes here
return 0; } Programming Basics
Comments • Single Line // • Block Comments /* comments */
/** * This is a * multiline comment */ Including Header Files
In C++, we often times need to include other libraries or files into our program so that we can have access to additional functionality • The #include keyword is used to indicate importing a file into our program (similar to Java import ) • This gives you access to things implemented in the c++ standard library • Ex: strings, cout, cin, etc…
#include
int main() {
// code goes here
return 0; } Basic I/O (cout) cout is part of the iostream c++ standard library. To use cout in a program you must include the header #include
• cout - characters out - prints characters to console
• In Java this was System.out.print( … );
• << - the stream insertion operator
• String Literal “” ex: “cat”
• A string literal is different than a string in that it does NOT have a memory address.
• endl - denotes a new line
• cout - an object responsible for printing out to the console
example: outputExample.cpp Basic I/O (cin) cin is part of the iostream c++ standard library. To use cin in a program you must include the header #include
• cin - characters in - reads in characters entered from the keyboard
• In Java this was where you used Scanner
• >> - the stream extraction operator
• Rules to be aware of with cin • When reading into an integer - will ignore leading whitespace and read until the first non-decimal character
• When reading into a floating point - will ignore leading whitespace then read until the first non-decimal character (will include decimal place)
• When reading into a single character - will ignore leading whitespace then read first character example: inputExample.cpp Example 1.2
#include
cout << "What is your age?: "; cin >> age; cout << "You are " << age << " years old" << endl;
return 0; } I/O Exercise
What will the output look like for each statement? int score = 20;
1. cout << “George’s score is” << score; cout << “Elroy’s score is” << score;
2. cout << “Welcome \n to Dunder Mifflin”;
I/O Exercise
What will the output look like for each statement? int score = 20;
1. cout << “George’s score is” << score; cout << “Elroy’s score is” << score;
George’s score is20Elroy’s score is20
2. cout << “Welcome \n to Dunder Mifflin”;
Welcome to Dunder Mifflin I/O Exercise int a; char b; float c; cin >> a >> b >> c; cout << a << endl << b << endl << c;
What would be printed if the user entered the following:
• 123b13.2 ?
• 129.11.129 ?
Operators
• An operator allows us to perform mathematical or logical computations one or more operands or values
Ex:
x = 5; // = operator
y = x + 2; // = and + operator Assignment Operator
Used to assign a value to a variable from right to left.
• The assignment operator is denoted by =
Ex:
int x = 5;
• Variables support reassignment to different values
• Other variables are not affected by changing the value of another
Ex: int x = 5; // x = 5 int y = x; // y = 5 x = 20; cout << “x = ” << x; cout << “y = ” << y;
Arithmetic Operators
Arithmetic Operators perform mathematical operations on their operands. The 5 arithmetic operators supported in C++ are:
+ Addition - Subtraction Ex: int x = 1 + 2; // x = 3 * Multiplication / Division int x = 10 % 3; // x = 1 % Modulo
Increment and Decrement
Ex: int x = 10; // x = 10 x++; ++x; // x = 12 x--; --x; // x = 10
examples: modulo.cpp increment.cpp Compound Operators
Compound Operators are equivalent to an assignment with one operation. They modify the current variable with some operation.
(+=, -=, *=, /=, %=, >>=, <<=, &=, ^=, |=)
x += 3; // x = x + 3
y *= 2; // y = y * 2 Relational Operators
Relational and Comparison Operators are used to compare two expressions. They will evaluate to true or false.
(==, !=, <, >, <=, >=)
(1 == 1); // true (1 != 1); // false (6 >= 6); // true (6 > 6); // false Logical Operators
Logical Operators are used along with Relational Operators to return a boolean result.
(!, &&, ||)
!(1 == 1) logical NOT (true && true) logical AND (true || false logical OR Bitwise Operators
Bitwise Operators modify variables using bit wise patterns
Operator Bitwise Description & Bitwise AND | Bitwise Inclusive OR ^ Bitwise Exclusive OR ~ NOT << Shift Left >> Shift Right
examples: binary.cpp Other C++ Operators
The full list of operators can be found at http:// www.cplusplus.com/doc/tutorial/operators/ Exercise
Write a program that asks a user to enter how many classes they are taking this semester. Then output the total amount of hours they are enrolled in.
Assume each class is 3 hours
solution: class_hours.cpp