<h2>Basics</h2>
<p>Basic syntax and functions from the C++ programming language.</p>
<h3>Boilerplate</h3>
<pre class="language-cpp"><code>#include &lt;iostream&gt;
using namespace std;

int main() {
cout &lt;&lt; "Welcome To CodeWithHarry";
return 0;
}</code></pre>
<h3>cout &lt;&lt;</h3>
<p>It prints output on the screen used with the insertion operator&nbsp;</p>
<pre class="language-cpp"><code>cout &lt;&lt; "This is C++ Programming";</code></pre>
<h3>cin &gt;&gt;</h3>
<p>It takes input from the user used with the extraction operator</p>
<pre class="language-cpp"><code>cin &gt;&gt; variable_name;</code></pre>
<h2>Data types</h2>
<p>The data type is the type of data</p>
<h3>Character type</h3>
<p>Typically a single octet(one byte). It is an integer type</p>
<pre class="language-cpp"><code>char variable_name;</code></pre>
<h3>Integer type</h3>
<p>The most natural size of integer for the machine</p>
<pre class="language-cpp"><code>int variable_name;</code></pre>
<h3>Float type</h3>
<p>A single-precision floating-point value</p>
<pre class="language-cpp"><code>float variable_name;</code></pre>
<h3>Double type</h3>
<p>A double-precision floating-point value</p>
<pre class="language-cpp"><code>double variable_name;</code></pre>
<h3>Void type</h3>
<p>Represents the absence of the type</p>
<pre class="language-cpp"><code>void</code></pre>
<h3>Boolean type</h3>
<pre class="language-cpp"><code>bool</code></pre>
<p>&lt;|AD|&gt;</p>
<h2>Escape Sequences</h2>
<p>It is a sequence of characters starting with a backslash, and it doesn't represent itself when used inside string literal.</p>
<h3>Alarm or Beep</h3>
<p>It produces a beep sound</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\a";</code></pre>
<h3>Backspace</h3>
<p>It adds a backspace</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\b";</code></pre>
<h3>Form feed</h3>
<pre class="language-cpp"><code>cout&lt;&lt;"\f";
</code></pre>
<h3>Newline</h3>
<p>Newline Character</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\n";</code></pre>
<h3>Carriage return</h3>
<pre class="language-cpp"><code>cout&lt;&lt;"\r";</code></pre>
<h3>Tab</h3>
<p>It gives a tab space</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\t";</code></pre>
<h3>Backslash</h3>
<p>It adds a backslash</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\\";</code></pre>
<h3>Single quote</h3>
<p>It adds a single quotation mark</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\'";</code></pre>
<h3>Question mark</h3>
<p>It adds a question mark</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\?";</code></pre>
<h3>Octal No.</h3>
<p>It represents the value of an octal number</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\nnn";</code></pre>
<h3>Hexadecimal No.</h3>
<p>It represents the value of a hexadecimal number</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\xhh";</code></pre>
<h3>Null</h3>
<p>The null character is usually used to terminate a string</p>
<pre class="language-cpp"><code>cout&lt;&lt;"\0";</code></pre>
<h2>Comments</h2>
<p>A comment is a code that is not executed by the compiler, and the programmer uses it to keep track of the code.</p>
<h3>Single line comment</h3>
<pre class="language-cpp"><code>// It's a single line comment</code></pre>
<h3>Multi-line comment</h3>
<pre class="language-cpp"><code>/* It's a 
multi-line
comment
*/</code></pre>
<h2>Strings</h2>
<p>It is a collection of characters surrounded by double quotes</p>
<h3>Declaring String</h3>
<pre class="language-cpp"><code>// Include the string library
#include &lt;string&gt;

// String variable
string variable1 = "Hello World";</code></pre>
<h3>append function</h3>
<p>It is used to concatenate two strings</p>
<pre class="language-cpp"><code>string firstName = "Harry ";
string lastName = "Bhai";
string fullName = firstName.append(lastName);
cout &lt;&lt; fullName;</code></pre>
<h3>length function</h3>
<p>It returns the length of the string</p>
<pre class="language-cpp"><code>string variable1 = "CodeWithHarry";
cout &lt;&lt; "The length of the string is: " &lt;&lt; variable1.length();
</code></pre>
<h3>Accessing and changing string characters</h3>
<pre class="language-cpp"><code>string variable1 = "Hello World";
variable1[1] = 'i';
cout &lt;&lt; variable1;</code></pre>
<p>&lt;|AD|&gt;</p>
<h2>Maths</h2>
<p>C++ provides some built-in math functions that help the programmer to perform mathematical operations efficiently.</p>
<h3>max function</h3>
<p>It returns the larger value among the two</p>
<pre class="language-cpp"><code>cout &lt;&lt; max(25, 140);</code></pre>
<h3>min function</h3>
<p>It returns the smaller value among the two</p>
<pre class="language-cpp"><code>cout &lt;&lt; min(55, 50);</code></pre>
<h3>sqrt function</h3>
<p>It returns the square root of a supplied number</p>
<pre class="language-cpp"><code>#include &lt;cmath&gt;

cout &lt;&lt; sqrt(144);</code></pre>
<h3>ceil function</h3>
<p>It returns the value of x rounded up to its nearest integer</p>
<pre class="language-cpp"><code>double a=ceil(1.9);</code></pre>
<h3>floor function</h3>
<p>It returns the value of x rounded down to its nearest integer</p>
<pre class="language-cpp"><code>double a=floor(1.02);</code></pre>
<h3>pow function</h3>
<p>It returns the value of x to the power of y</p>
<pre class="language-cpp"><code>int a=pow(x, y);</code></pre>
<h2>Decision Making Instructions</h2>
<p>Conditional statements are used to perform operations based on some condition.</p>
<h3>If Statement</h3>
<pre class="language-cpp"><code>if (condition) {
// This block of code will get executed, if the condition is True
}</code></pre>
<h3>If-else Statement</h3>
<pre class="language-cpp"><code>if (condition) {
// If condition is True then this block will get executed
} else {
// If condition is False then this block will get executed
}</code></pre>
<h3>if else-if Statement</h3>
<pre class="language-cpp"><code>if (condition) {
// Statements;
}
else if (condition){
// Statements;
}
else{
// Statements
}</code></pre>
<h3>Ternary Operator</h3>
<p>It is shorthand of an if-else statement.</p>
<pre class="language-cpp"><code>variable = (condition) ? expressionTrue : expressionFalse;</code></pre>
<h3>Switch Case Statement</h3>
<p>It allows a variable to be tested for equality against a list of values (cases).</p>
<pre class="language-cpp"><code>switch (expression) 
{
case constant-expression: 
statement1;
statement2;
break;
case constant-expression: 
statement;
break;
...
default: 
statement;
}</code></pre>
<p>&lt;|AD|&gt;</p>
<h2>Iterative Statements</h2>
<p>Iterative statements facilitate programmers to execute any block of code lines repeatedly and can be controlled as per conditions added by the programmer.</p>
<h3>while Loop</h3>
<p>It iterates the block of code as long as a specified condition is True</p>
<pre class="language-cpp"><code>while (/* condition */)
{
/* code block to be executed */
}</code></pre>
<h3>do-while loop</h3>
<p>It is an exit controlled loop. It is very similar to the while loop with one difference, i.e., the body of the do-while loop is executed at least once even if the condition is False</p>
<pre class="language-cpp"><code>do
{
/* code */
} while (/* condition */);</code></pre>
<h3>for loop</h3>
<p>It is used to iterate the statements or a part of the program several times. It is frequently used to traverse the data structures like the array and linked list.</p>
<pre class="language-cpp"><code>for (int i = 0; i &lt; count; i++)
{
/* code */
}</code></pre>
<h3>Break Statement</h3>
<p>break keyword inside the loop is used to terminate the loop</p>
<pre class="language-cpp"><code>break;</code></pre>
<h3>Continue Statement</h3>
<p>continue keyword skips the rest of the current iteration of the loop and returns to the starting point of the loop</p>
<pre class="language-cpp"><code>continue;</code></pre>
<h2>References</h2>
<p>Reference is an alias for an already existing variable. Once it is initialized to a variable, it cannot be changed to refer to another variable. So, it's a const pointer.</p>
<h3>Creating References</h3>
<pre class="language-cpp"><code>string var1 = "Value1"; // var1 variable
string &amp;var2 = var1; // reference to var1</code></pre>
<h2>Pointers</h2>
<p>Pointer is a variable that holds the memory address of another variable</p>
<h3>Declaration</h3>
<pre class="language-cpp"><code>datatype *var_name; 

var_name = &amp;variable2;</code></pre>
<h2>Functions &amp; Recursion</h2>
<p>Functions are used to divide an extensive program into smaller pieces. It can be called multiple times to provide reusability and modularity to the C program.</p>
<h3>Function Definition</h3>
<pre class="language-cpp"><code>return_type function_name(data_type parameter...){ 
//code to be executed 
}</code></pre>
<h3>Function Call</h3>
<pre class="language-cpp"><code>function_name(arguments);</code></pre>
<h3>Recursion</h3>
<p>Recursion is when a function calls a copy of itself to work on a minor problem. And the function that calls itself is known as the Recursive function.</p>
<pre class="language-cpp"><code>void recurse()
{
... .. ...
recurse();
... .. ...
}</code></pre>
<h2>Object-Oriented Programming</h2>
<p>It is a programming approach that primarily focuses on using objects and classes. The objects can be any real-world entities.</p>
<h3>class</h3>
<pre class="language-cpp"><code>class Class_name {
public: // Access specifier
// fields
// functions
// blocks
};</code></pre>
<h3>object</h3>
<pre class="language-cpp"><code>Class_name ObjectName;</code></pre>
<h3>Constructors</h3>
<p>It is a special method that is called automatically as soon as the object is created.</p>
<pre class="language-cpp"><code>class className { // The class
public: // Access specifier
className() { // Constructor
cout &lt;&lt; "Code With Harry";
}
};

int main() {
className obj_name; 
return 0;
}</code></pre>
<h3>Encapsulation</h3>
<p>Data encapsulation is a mechanism of bundling the data, and the functions that use them and data abstraction is a mechanism of exposing only the interfaces and hiding the implementation details from the user.</p>
<pre class="language-cpp"><code>#include&lt;iostream&gt; 
using namespace std; 
class ExampleEncap{ 
private: 
/* Since we have marked these data members private, 
* any entity outside this class cannot access these 
* data members directly, they have to use getter and 
* setter functions. 
*/ 
int num; 
char ch; 
public: 
/* Getter functions to get the value of data members. 
* Since these functions are public, they can be accessed 
* outside the class, thus provide the access to data members 
* through them 
*/ 
int getNum() const { 
return num; 
} 
char getCh() const { 
return ch; 
} 
/* Setter functions, they are called for assigning the values 
* to the private data members. 
*/ 
void setNum(int num) { 
this-&gt;num = num; 
} 
void setCh(char ch) { 
this-&gt;ch = ch; 
} 
}; 
int main(){ 
ExampleEncap obj; 
obj.setNum(100); 
obj.setCh('A'); 
cout&lt;&lt;obj.getNum()&lt;&lt;endl; 
cout&lt;&lt;obj.getCh()&lt;&lt;endl; 
return 0; 
}</code></pre>
<p>&lt;|AD|&gt;</p>
<h2>File Handling</h2>
<p>File handling refers to reading or writing data from files. C provides some functions that allow us to manipulate data in the files.</p>
<h3>Creating and writing to a text file</h3>
<pre class="language-cpp"><code>#include &lt;iostream&gt;
#include &lt;fstream&gt;
using namespace std;

int main() {
// Create and open a text file
ofstream MyFile("filename.txt");

// Write to the file
MyFile &lt;&lt; "File Handling in C++";

// Close the file
MyFile.close();
}</code></pre>
<h3>Reading the file</h3>
<p>It allows us to read the file line by line</p>
<pre class="language-cpp"><code>getline()</code></pre>
<h3>Opening a File</h3>
<p>It opens a file in the C++ program</p>
<pre class="language-cpp"><code>void open(const char* file_name,ios::openmode mode);</code></pre>
<h3>in</h3>
<p>Opens the file to read(default for ifstream)</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::in)</code></pre>
<h3>out</h3>
<p>Opens the file to write(default for ofstream)</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::out)</code></pre>
<h3>binary</h3>
<p>Opens the file in binary mode</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::binary)</code></pre>
<h3>app</h3>
<p>Opens the file and appends all the outputs at the end</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::app)</code></pre>
<h3>ate</h3>
<p>Opens the file and moves the control to the end of the file</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::ate)</code></pre>
<h3>trunc</h3>
<p>Removes the data in the existing file</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::trunc)</code></pre>
<h3>nocreate</h3>
<p>Opens the file only if it already exists</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::nocreate)</code></pre>
<h3>noreplace</h3>
<p>Opens the file only if it does not already exist</p>
<pre class="language-cpp"><code>fs.open ("test.txt", std::fstream::noreplace)</code></pre>
<h3>Closing a file</h3>
<p>It closes the file</p>
<pre class="language-cpp"><code>myfile.close()</code></pre>
<h2>Exception Handling</h2>
<p>An exception is an unusual condition that results in an interruption in the flow of the program.</p>
<h3>try and catch block</h3>
<p>A basic try-catch block in python. When the try block throws an error, the control goes to the except block</p>
<pre class="language-cpp"><code>try {
// code to try
throw exception; // If a problem arises, then throw an exception
}
catch () {
// Block of code to handle errors
}</code></pre>
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