#Code2 create c++ for beginners

Basic terms in coding
• What is programming?
• Programming language is a tool used to create a program by writing human
like language in a specific structure (syntax) using an editor that will translate
the human language to binary language of zeros and ones, which is the
computer language.
• Programming is using a code or source code, which is a sequence of
instructions to develop a program that will provide an output solution using
several tools such as a programming language & programming language
editor.
• output: The messages printed to the user by a program.
• console: The text box onto which output is printed.
• syntax: The set of legal structures and commands that can be used in a particular
programming language. 2

What is the differences between C#, C++,
and C?
• C and C++ differences:
• C++ was built as an extension of C, which means it can run most C code.
• C++ supports reference variables, which C does not.
• C uses functions for input and output, whereas C++ uses objects for input and output.
• C does not provide error or exception handling, but C++ does.
• As an object-oriented language, C++ supports polymorphism, encapsulation, and inheritance, while C does not.
• C++ and C# differences:
• C++ compiles into machine code, while C# compiles to CLR, which is interpreted by ASP.NET.
• C++ can be used on any platform, though it was originally designed for Unix-based systems. C# is standardized but is
rarely used outside of Windows environments.
• C++ can create stand-alone and console applications. C# can create a console, Windows, ASP.NET, and mobile
applications, but cannot create stand-alone apps.
• C++ requires you to handle memory manually, but C# runs in a virtual machine which can automatically handle
memory management. 3

Structure of a C++ Program
4
// my first program in C++
#include <iostream>
using namespace std;
int main ()
{
cout << "Hello World! ";
return (0);
}
Used to group
statements
Comment line
Execution begin
Standard output stream in C++
• Select Execute> Compile,
to compile your program.
• Select Execute> Run, to
run your program.
Hello World!
Output:

Comments
• C++ support two ways to insert comments:
• // line comment
• /* block Comment */
5
/* my second program in C++
With more comment */
#include <iostream>
int main (){
cout << "Hello World! "; //says Hello World
cout << "I am a C++ program "; // says I am a C++ program
}
Hello World! I am a C++ program
Example: Output:

Good Programming Practice
• Every program should begin with a comment that explains the purpose of
program, author and creation date and last update date.
• Example:
/* Created By: Maryam AlMahdi
Creation Date: 7 July 2021
Last Updated Date: 29 July 2021
Description: ................
*/
6

Output Statement: (cout)
7
cout<<expression<<expression…..;
cout<< “First sentence. ”;
cout<< “Second sentence. Third sentence.”;
Example:
After adding Escape Sequences:
cout<< “First sentence. n ”;
cout<< “Second sentence. n Third sentence.”;
cout<< “First sentence.”;
cout<< “nSecond sentence. t Third sentence.”;
cout<< 123;
cout<< “The result is =“ << 12+14;

Output Statement:
Escape Sequences
8
n New line
r Carriage return
t tabulation
v Vertical tabulation
b backspace
f Page feed
a Alert (beep)
’ Single quote(‘)
” Double quote (“)
? Question (?)
Inverted slash

Variables, Constants, Data types
• Variable:
A memory location whose content may change during program execution.
• Constant:
A memory location whose content is not allowed to change during program
execution.
• An Identifier:
is a sequence of one or more letters, digits or underline symbols ( _ ), and must
begin with a letter or underscore.
9

Variables, Constants, Data types:
Identifier
• The length of an identifier is not limited, although for some compilers only the 32
first characters of an identifier are significant (the rest are not considered).
• Neither spaces nor marked letters can be part of an identifier. Only letters, digits
and underline characters are valid.
• Identifier should not match any reserved key word of the C++ language.
• The C++ language is "case sensitive", that means that an identifier written in
capital letters is not equivalent to another one with the same name but written in
small letters.
10

Declaration of Variable
11
DataType identifier, identifier,….;
Example:
int a;
char ch,x,y;
short NumberOfSons;
int MyAccountBalance;

Variables, Constants, Data types: Data Type
12
Name Bytes* Description Range
char 1 character or integer 8 bits length. signed: -128 to 127 unsigned: 0 to 255
short 2 integer 16 bits length. signed: -32768 to 32767 unsigned: 0
to 65535
long 4 integer 32 bits length. signed:-2147483648 to 2147483647
unsigned: 0 to 4294967295
int * Integer. Its length traditionally depends on the length of the system's Word type,
thus in MSDOS it is 16 bits long, whereas in 32 bit systems (like Windows
9x/2000/NT and systems that work under protected mode in x86 systems) it is 32
bits long (4 bytes).
See short, long
float 4 floating point number. 3.4e + / - 38 (7 digits)
double 8 double precision floating point number. 1.7e + / - 308 (15 digits)
Long double 10 long double precision floating point number. 1.2e + / - 4932 (19 digits)
bool 1 Boolean value. It can take one of two values: true or false NOTE: this is a type
recently added by the ANSI-C++ standard. Not all compilers support it. Consult
section bool
type for compatibility information.
true or false
string 8 stores text, such as "Hello World". String values are surrounded by double quotes.
This is not a built-in type, but it behaves like one in its most basic usage
“text”

Declaration of Variable
13
// operating with variables
#include <iostream> using namespace std;
int main ()
{ // declaring variables:
int a,b;
int result;
// process:
a = 5;
b = 2;
a = a + 1;
result = a - b;
// print out the result:
cout << result;
// terminate the program:
return(0)
}
output is 4

Initialization of variables
14
• Example:
int x=0;
int x(0);
int a=5, b=2;
DataType= initial_value;
DataType (initial_value);
// operating with variables
#include <iostream> using namespace std;
int main ()
{// declaring variables:
int result;
// process:
int a(5);
int b(2);
a = a + 1;
result = a - b;
// print out the result:
cout << result;
// terminate the program:
}
Or int a(5),b(2);

Output Statement (Cont’d)
15
• Examples
cout<<expression<<expression..;
cout<<”Results”; //prints Results on screen
cout<<120; //prints number 120 on screen
cout<<a; //prints the content of variable a on screen
cout<<“a-b”<<result;
cout<<a<<“-”<<b<<“=“<<result;

Declared Constant (const)
• With the const prefix you can declare constants with a specific type
exactly as you would do with a variable:
• Examples:
const int width = 100;
const int zip = 12440;
16
const dataTypes identifier = value;

Operators
• The Assignment (=) operator serves to assign a value to a variable.
• Assignation operation always takes place from right to left and never
at the inverse.
17
Variable = expression ;

Operators: Assignment operator
• Examples:
18
int a,b,c;
a=10;
b=4;
a=b;
b=7;
a=2+(b=5); // is equivalent to b=5;
a=2+b;
a=b=c=5; // assigns 5 to the three variables a, b and c.
cout<<a,b,c;

Operators:
Arithmetic and Relational Operators
• Arithmetic operators ( +, -, *, /, %)
Module (%) is the operation that gives the remainder of a division of two integer values,
• Example:
• Relational operators ( ==, !=, >, <, >=, <= )
• The result of a relational operation is a Boolean value that can only be true(1) or false(0).
19
int a=11%3; //a=2
cout<<a;
int a=(11<3); //will give us 0 as false
cout<<a<<“n”;
int b=(11>3); //will give us 1 as true
cout<<b;

Operators:
Logic operators
• Logic operators ( !, &&, || ).
They correspond with Boolean logic operations NOT, AND and OR Respectively
• Examples:
20
First Operand
a
Second
Operand b
result
a && b
result
a || b
true true true true
true false false true
false true false true
false false false false
int a( (5 == 5) && (3 > 6) ); // returns false ( true && false ).
cout<<a<<”n”;
int b( (5 == 6) || (3 != 6)); // returns true ( true || false ).
cout<<b;

Operators
• Compound assignation operators
(+=, -=, *=, /=, %=, >>=, <<=, &=, ^=, |=)
• Increase(++) and decrease (--)
• They increase or reduce by 1 the value stored in a variable.
• They are equivalent to +=1 and to -=1, respectively.
• They can be used both as a prefix or (++a) as a suffix(a++).
21
value += increase; // is equivalent to value=value + increase;
a -= 5; // is equivalent to a=a-5;
a /= b; // is equivalent to a=a/b;
price *= units + 1; // is equivalent to price = price * (units + 1);

Operators
• Example 1:
equivalent to equivalent to
• Example 2: Example 3:
22
a++; a=a+1; a+=1;
int B=3;
int A=++B;
// A is 4, B is 4
cout<<A<<“n”<<B;
int B=3;
int A=B++;
// A is 3, B is 4
cout<<A<<“n”<<B;

Operators : Priority of operators
Priority Operator Description Associativity
1 () [ ] Left
2 ++ -- increment/decrement Right
~ Complement to one (bitwise)
! unary NOT
& * Reference and Dereference (pointers)
(type) Type casting
+ - Unary sign
3 * / % arithmetical operations Left
4 + - arithmetical operations Left
5 < <= > >= Relational operators Left
6 == != Relational operators Left
7 && || Logic operators Left
10 = += -= *= /= %=
>>= <<= &= ^= |=
Assignation Right
11 , Comma, Separator Left 23

Input Statement: (cin)
• cin only process the input from the keyboard once the RETURN key
has been pressed.
• Example 1:
• Example 2:
equivalent to
24
cin>> variable >>variable .... ;
int age;
cin >> age;
cin>> a >> b;
cin>> a;
cin>> b;

Input Statement: (cin)
25
#include <iostream>
/* Created By: Maryam AlMahdi
Creation Date: 29 July 2021
Description: .. */
int main ()
{
int i;
cout << "Please enter an integer value: ";
cin >> i;
cout << "The value you entered is " << i;
cout << " and its double is " << i*2 << "n";
return 0;
}
Please enter an integer value: 702
The value you entered is 702 and its double is 1404.

Control Statements: Single-Selection statement
• It is used to execute an instruction or block of instructions only if a
condition is fulfilled.
• If the condition is false, statement is ignored (not executed) and the
program continues on the next instruction after the conditional
structure.
• Example 1: Example2:
26
If (condition ) statement
if (x == 100)
{
cout << "x is ";
cout << x;
}
if (x == 100)
cout << "x is 100";

Control Statements: Double-Selection statement
• Example1: Example2:
27
If (condition ) statement1 else statement2
if (x == 100)
cout << "x is 100";
else
cout << "x is not 100";
if (x > 0)
cout << "x is positive";
else if (x < 0)
cout << "x is negative";
else
cout << "x is 0";

Let’s review what we’ve learned
• Write a program that includes the following:
x=“Hello”
Name= takes input from the user
Print the statement Hello + the user name.
28

• Solution:
#include <iostream>
int main()
{
string x="Hello";
string Name;
cout<<"What is your name?"<<"t";
cin>> Name;
cout<<x<<"t"<<Name;
return 0;
}
29
Quick note:
In C++ every data type
has a specific number of
bytes to store as shown
in this hypertext link of
slide 13.Date Types.

• Write a program as showing below:
a=2
b=5
c=8
Use if else statement to print “a is less than c”.
30

• Solution:
#include <iostream>
int main()
{
int a,b,c;
a=2;
b=5;
c=8;
if (a<c)
cout<<"a is less than c";
else
cout<<"a is greater than c";
return 0;
}
31

References
• Information Technology Infrastructure, Dr. Maryam AlOtaibi.
• A Complete guide to Programming in C++ y Ulla Kirch-Prinz & Peter
Prinz.
32

Contact info
• Maryam AlMahdi
• E-mail: mariam.almahdi@outlook.com
• Instagram: @gdgkwt_maryam
33

Variables, Constants, Data types: Data Type
34
Name Bytes* Description Range
char 1 character or integer 8 bits length. signed: -128 to 127 unsigned: 0 to 255
short 2 integer 16 bits length. signed: -32768 to 32767 unsigned: 0
to 65535
long 4 integer 32 bits length. signed:-2147483648 to 2147483647
unsigned: 0 to 4294967295
int * Integer. Its length traditionally depends on the length of the system's Word type,
thus in MSDOS it is 16 bits long, whereas in 32 bit systems (like Windows
9x/2000/NT and systems that work under protected mode in x86 systems) it is 32
bits long (4 bytes).
See short, long
float 4 floating point number. 3.4e + / - 38 (7 digits)
double 8 double precision floating point number. 1.7e + / - 308 (15 digits)
Long double 10 long double precision floating point number. 1.2e + / - 4932 (19 digits)
bool 1 Boolean value. It can take one of two values: true or false NOTE: this is a type
recently added by the ANSI-C++ standard. Not all compilers support it. Consult
section bool
type for compatibility information.
true or false
string 8 stores text, such as "Hello World". String values are surrounded by double quotes.
This is not a built-in type, but it behaves like one in its most basic usage
“text”

#Code2 create c++ for beginners

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