Introduction to Programming with C++

Welcome to Introduction to Programming with C++

Introduction to programming with C++

Installing Visual Studio 2017

How to install Visual Studio 2017 Community Edition

Link to page:https://visualstudio.microsoft.com/vs/older-downloads/

Starting with C++ & Programming Languages

Programming Languages

In this unit, we will examine programming languages and Visual C++. We will exam a typical C++ program and how the C++ application works.
Before we can start developing, we need to understand the process of communication between program and machine.

Programming Structure

First program “Hello World”

C++ programs follow a standard layout (In most cases). They start with Libraries, default function, and comments.
First, create a project using C++ and select an empty project.

Libraries & Pre-processor

/* A comment block should be the first thing in a file! Comments are ignored by the compiler.

They help explain the code. It should summarize what the program does.

It should identify who wrote the program and when it was written.

*/ // Pre-Processor directives should follow the comment block. //

A pre-processor directive is an instruction to the preprocessor (which runs before the compiler) as to where to find useful definitions used by the code in the file. //

For example, the following line tells the preprocessor to bring in all the definitions from the iostream header file provided by the system.

// This is where the cin and cout input and output streams come from that enable keyboard input and console output.

#include <iostream>

using namespace std;

int main() {

// Your code here

return 0;

}

Stream insertion operator & Es’cape sequences

Stream insertion operator The << operator is known as the Stream insertion Operator. So, when the program executes the << display the values to the right of the operator. Example
cout << “name”;
The console displays the value “name”
Es’cape sequences

Common elements in programming languages

What are the elements of a program -Key Words examples using, namespace, int, string, void … -Programmer-Defined Identifiers examples are name, firstName, sum, num1, numberOne … -Operators example +, _, *. / and <<, >> – Punctuation example string name, firstName, lastName; -Syntax rules of grammar use when writing a program C++ Keywords This is a list of reserved keywords in C++. Since they are used by the language, these keywords are not available for re-definition or overloading.

Input, Process and output (IPO)

Input Process & Output –

IPO Model

// IPO Input, Process and Output

//Input -> Gather input data from keyboard from files and Disk Drives

//Process the input data

//Display the results as output

// Procedural programming focus on the process ( Procedures or functions are written to process data)

Input

Process

Output

Hours

Rate

totalPayCheck

ask user for input hours

ask user to input rate

TotalPayCheck = Hours * Rate;

Cout << “you get paid” << totalPayCheck << endl;

You get pay 200

Variable Names

The name of a variable in programming should represent the purpose of the variable in the program.

For example, when you are adding two numbers.

First Number should be call number1 or num1 or numberOne or _num1
num1 First letter should be lower case
_num1 you can use underscore to start the name of a variable
numberOne If you have more than one word to describe the variable the second word should start with Upper case
@num1 can NOT use special characters to begin the name of a variable
1Num can NOT begin the name with a number

Integer Data Types

Integer Data Types
// holds whole numbers as 5, 7, 230
int num1; //-2, 147.483.647 to +2,147.483.647
unsigned int; // hold only 0 up no negative numbers
short num2;// 2 bytes negative values all the way to positive -32,7698 to + 32.767
long num3; // 4 bytes – 2, 147.483.647 to + 2, 147.483.647
unsigned long num4; //hold only 0 up no negative numbers

https://www.geeksforgeeks.org/c-data-types/

Floating Data Types

Floating Data Types

Float
double
long double
hold real numbers 12.50 -3.5
all floating-point numbers are signed

float num1; //4 bytes, +-3.
double num2; //8 bytes hold only 0 up no negative numbers
long double num3;// 8 bytes

//Float Data Types – float double – long double
//hold real numbers 12.50 – 3.5
//all floating – point numbers are signed
float distance = 1.45674837E11;
double mass = 1.98E30;
long double num3 = 4.963737;

Char & String Data Types

Char & String Data Types

Character data type

This data type stores character values. It takes 1 byte in memory and is used to represent letters, numbers, punctuation marks, and a few other symbols.

These types of values are typically given in single quotes.

EXAMPLE

‘a’, ‘5’, ‘#’, etc

Bool Data Types

Bool Data Types

Represent values that are TRUE or FALSE

Booleans are variables that are stored as small integers

False represents 0

True represents 1

Arithmetic Operators

Arithmetic Operators

//Binary Arithmetic Operators

+ addition, – subtraction, * multiplication, / division, % modulus

// input
double regularWeekPayCheck; // how much we get pay a week
double rate = 18.25;// 18.25 + 9.125 = 27.78
double hours = 40.0;
//————————-
double overtime;
double overtimeRate = 27.78;
double overtimeHours = 10.0;
//————————-
double totalWeekWages;
// module
int num1 = 13;
int num2 = 5;
int totalModule;
//process
regularWeekPayCheck = hours * rate;
// overtime
overtime = overtimeRate * overtimeHours;
//— total week wages

// process for module
totalModule = num1 % num2;//

totalWeekWages = regularWeekPayCheck + overtime;
// output
cout << “Your week pay check is:\t” << regularWeekPayCheck << endl;
cout << “Your week overtime amount is:\t” << overtime << endl;

cout << “Your total week pay check is:\t” << totalWeekWages << endl;

cout << ” you total is” << totalModule << endl;
return 0;

3 Expressions & Interactivity

Cin Object & Constants

// cin object Standard input object
// requires iostream file
// reads input from the keyboard
//information retrieved from cin with >> operator
// input is store in one or more variables

Rules of Operator Precedence

Evaluation of a Second-Degree Polynomial

To develop a better understanding of the rules of operator precedence, consider the evaluation of a second-degree polynomial y = ax 2 + bx + c:

The circled numbers under the statement indicate the order in which C++ applies the operators. There is no arithmetic operator for exponentiation in C++, so we’ve represented x 2 as x * x. We’ll soon discuss the standard library function pow (“power”) that performs exponentiation. Because of some subtle issues related to the data types required by pow, we defer a detailed explanation of pow until Chapter 6.

Suppose variables a, b, c and x in the preceding second-degree polynomial are initialized as follows: a = 2, b = 3, c = 7 and x = 5. Figure 2.11 illustrates the order in which the operators are applied and the final value of the expression.

Making Decisions

Allows statements to be conditionally executed or skipped over
Models the way we mentally evaluate situations:
If I have valid ID I am welcome into the gym
else I should try again

Relational Operators

Boolean expressions – true or false
Used to compare numbers to determine relative order

Operators:

>	Greater than
<	Less than
>=	Greater than or equal to
<=	Less than or equal to
==	Equal to
!=	Not equal to

Boolean expressions – true or false
Examples:

12 > 5 is true

7 <= 5 is false

if x is 10, then

x == 10 is true,

x != 8 is true, and

x == 8 is false

Nested if Statements

The if and else statements are used in C++ for decision making. They allow your program to execute certain code only when a specific condition is true.

`if` Statement

The if statement checks a condition.
If the condition is true, the code block inside the if statement is executed.
If the condition is false, the code block inside the if statement is skipped.

`else` Statement

The else statement is used to execute a block of code if the condition in the if statement is false.
It comes immediately after an if statement.

For example:

#include <iostream>
using namespace std;

int main() {
int number;

cout << “Enter a number: “;
cin >> number;

if (number > 0) {
// This block will execute if number is greater than 0
cout << “The number is positive.” << endl;
} else if (number < 0) {
// This block will execute if number is less than 0
cout << “The number is negative.” << endl;
} else {
// This block will execute if number is equal to 0
cout << “The number is zero.” << endl;
}

return 0;
}

Stay connected for Arrays, Function, classes, object and more...

Conclusion

Thank you for participation in this introduction to C++. There is some more to covert. If you have fun with this tutorials I would recommend you to read the suggested books and practice.

Book Suggestions: