03. Getting started with C++

History

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• C++ is a cross-platform language that can be used to create a high-performance applications.
• C++ was developed by Bjarne Stroustrup, in 1979 at bell Labs as an extension to the the C as a Low-Level Language .
• C++ gives programmers a high level of control over system resources and memory.
• The language was updated multiple times leading to various C++11, C++14, C++17, C++20, C++23.

Applications

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• C++ can be found in code of operating systems
• Graphical User Interfaces and embedded systems
• Many gaming engines are written in C++
• Web browsers like Mozilla, Chrome are written in C++
• Banking applications Libraries & Frameworks for Machine learning like tensor-flow by google.

Deep dive into the Boilerplate code:

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Boilerplate code:

include<iostream>
using namespace std;
 
int main(){
	//your code goes here
	cout << "Hello World";
	return 0;
}

#include : Pre-processor Directive : Gives instruction to the compiler for the pre-processing of the code.

iostream : Header file : For adding additional functionality in your code using a pre-written code file.

using namespace std : C++ standard namespace like cout, cin etc.

cout : Cout object : We want to output something in the console or the terminal.

int main() : Functions : Entry point : program starts executing from the main & any logic that you will define will go in the main. Each function will return something.

return 0 : defines successful execution of the main function.

NOTE

Compilation happens for every line which is line 1 - 7. Execution happens for line 4 - 7.

Input -Output

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Variables

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To store data from user input we need to create buckets in the memory, the buckets are called variables. Each variable is of a certain datatype.

#include<iostream>
using namespace std;
 
int main(){
	//creating variables
	int a, b, c;
 
	//reading inputs
	cin >> a;
	cin >> b;
	cin >> c;
 
	## outputs
	cout << "A:" << a << "B:" << b << "C:" << c << endl;
 
	//sum
	int sum  = a + b + c;
	cout << sum << endl;
	// optional : cout << (a + b + c) << endl;
return 0;
}

FAQ

C++ is a case sensitive language.

Comments

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Single line comment :

// this is a comment

Multi line comment :

/*
This is a multi line
commment in C++
*/