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C++ Introduction
course content

Course Content

C++ Introduction

C++ Introduction

1. Getting Started
Why to Learn C++What is C++Entry Point of a ProgramStandard Library and FilesPreprocessor DirectivesThe First Program
2. Variables and Data Types
Introduction to VariablesData TypesNumerical Data TypesIntroduction to StringIntroduction to ArraysKeywords sizeof(), auto and typedefWorking with the Array
3. Introduction to Operators
Simple OperatorsA Little MathLogical OperatorsCompound Assignment OperatorPracticing Math Basics
4. Introduction to Program Flow
If...else StatementTernary OperatorSwitch StatementWhile LoopDo...while LoopFor LoopFibonacci Number with Loops
5. Introduction to Functions
What are Functions?Type of FunctionsReturn Statement in FunctionsFunctions With Arguments Simple Function

bookIf...else Statement

The if...else construct in programming allows your program to take different paths and manage various potential outcomes.

It consists of two essential components: a condition and the corresponding actions or consequences based on that condition.

Here's an illustration:

cpp

main

copy

              
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#include<iostream>

int main()
{
	int var = 13;

	/* If my variable equals 13,
	   then print "OKAY", and
	   change variable to 15 */

	if (var == 13)
	{
		std::cout << "13 == 13, it is OKAY" << std::endl;
		var = 15;
    }

	/* New value of variable (15) doesn't equal 13,
	   then print "NOT OKAY" */

	if (var != 13)
	{
		std::cout << "15 != 13, it is NOT OKAY" << std::endl;
	}
}

Here, we use the 2-lines comment.

There is also a handling of the "opposite" case using else:

cpp

main

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#include<iostream>

int main()
{
	int var = 200;

	/* If my variable equals 13,
	   then print "OKAY" */

	if (var == 13)
	{
		std::cout << "My variable equals 13, it is OKAY" << std::endl;
	}

	/* If my variable doesn`t equal 13,
	   then print "NOT OKAY" */

	else
	{
		std::cout << "My variable doesn't equal 13, it is NOT OKAY" << std::endl;
	}
}

There can be other if...else inside the if...else:

cpp

main

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#include<iostream>

int main()
{
	int var = 15;

	if (var == 15)                 
  	{
		//then
		var = 15 + 200; 

		if (var == 300)
      	{
			//then
			std::cout << "OKAY" << std::endl;
		}
      
		// otherwise
		else
		{
			std::cout << "NOT OKAY" << std::endl;
		}
	}
}

You can also use the else if construct:

cpp

main

copy

              
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#include<iostream>

int main()
{
	int var = 50;

	if (var == 15)
	{
		std::cout << "var equals 15" << std::endl;
	}
	else if (var == 50)
	{
		std::cout << "var equals 50" << std::endl;
	}
	else if (var == 89)
	{
		std::cout << "var equals 89" << std::endl;
	}
	else if (var == 215)
	{
		std::cout << "var equals 215" << std::endl;
	}
}
What will the program output?

What will the program output?

Select the correct answer

Everything was clear?

How can we improve it?

Thanks for your feedback!

Section 4. Chapter 1
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