C# If (How it Works for Developers)

Understanding the If Statement

The if statement is a fundamental concept in programming. It is used to make decisions in code based on a certain condition. The basic syntax of an if statement in C# is as follows:

if (Boolean expression)
{
    // Statements to execute if the Boolean expression is true
}

if (Boolean expression)
{
    // Statements to execute if the Boolean expression is true
}

The if statement checks that the given Boolean expression evaluates to true. If it does, the code inside the statement block (the code enclosed in the curly braces) is executed. If the Boolean expression evaluates to false, the code inside the statement block is skipped.

if (Boolean expression)
{
    // Statements to execute if the Boolean expression is true
}
else
{
    // Statements to execute if the Boolean expression is false
}

if (Boolean expression)
{
    // Statements to execute if the Boolean expression is true
}
else
{
    // Statements to execute if the Boolean expression is false
}

using System;

class Program
{
    static void Main(string[] args)
    {
        int age = 21;

        if (age >= 18)
        {
            Console.WriteLine("You are eligible to vote!");
        }
        else
        {
            Console.WriteLine("Sorry, you are not eligible to vote.");
        }
    }
}

using System;

class Program
{
    static void Main(string[] args)
    {
        int age = 21;

        if (age >= 18)
        {
            Console.WriteLine("You are eligible to vote!");
        }
        else
        {
            Console.WriteLine("Sorry, you are not eligible to vote.");
        }
    }
}

Working with Boolean Expressions

In C#, you can use various types of Boolean expressions to create more complex conditions. Some commonly used conditional operators include:

• ==: Equality
• !=: Inequality
• <: Less than
• >: Greater than
• <=: Less than or equal to
• >=: Greater than or equal to

Let's take a look at an example. Suppose you want to write a program that checks if a number is positive, negative, or zero. The following code snippet uses if statements and conditional operators to achieve this:

using System;

class Program
{
    static void Main(string[] args)
    {
        int number = 0;

        if (number > 0)
        {
            Console.WriteLine("The number is positive.");
        }
        else if (number < 0)
        {
            Console.WriteLine("The number is negative.");
        }
        else
        {
            Console.WriteLine("The number is zero.");
        }
    }
}

using System;

class Program
{
    static void Main(string[] args)
    {
        int number = 0;

        if (number > 0)
        {
            Console.WriteLine("The number is positive.");
        }
        else if (number < 0)
        {
            Console.WriteLine("The number is negative.");
        }
        else
        {
            Console.WriteLine("The number is zero.");
        }
    }
}

In the above example, we first declare an integer variable named number and assign it the value of 0. We then use an if statement to check if the number is greater than 0. For a true value, we print "The number is positive." For false values, we move on to the else if statement, which checks if the number is less than 0. If this condition is true, we print "The number is negative." Finally, if none of the previous conditions are met, we reach the else block, which prints "The number is zero."

using System;

class Program
{
    static void Main(string[] args)
    {
        int age = 23;
        bool isStudent = true;

        if ((age >= 65) || (isStudent && (age >= 18 && age <= 25)))
        {
            Console.WriteLine("You are eligible for the discount!");
        }
        else
        {
            Console.WriteLine("Sorry, you are not eligible for the discount.");
        }
    }
}

using System;

class Program
{
    static void Main(string[] args)
    {
        int age = 23;
        bool isStudent = true;

        if ((age >= 65) || (isStudent && (age >= 18 && age <= 25)))
        {
            Console.WriteLine("You are eligible for the discount!");
        }
        else
        {
            Console.WriteLine("Sorry, you are not eligible for the discount.");
        }
    }
}

Generating PDFs with IronPDF: A Relevant Application of If-Else Statements

Now that you have a solid grasp on the C# if-else statement, let's explore a practical application involving the IronPDF library, which allows you to work with PDF files in C# applications seamlessly.

IronPDF is a powerful .NET library that allows you to create, edit, and extract content from PDF files within your C# applications.

In this example, we will create a simple PDF invoice generator that applies different tax rates based on the customer's location. This scenario provides an excellent opportunity to utilize if-else statements.

First, install IronPDF via NuGet by running the following command:

Install-Package IronPdf

Next, let's create a simple program that generates an invoice with different tax rates for customers in different regions:

using System;
using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        string customerLocation = "Europe";
        double taxRate;

        // Determine tax rate based on customer location
        if (customerLocation == "USA")
        {
            taxRate = 0.07;
        }
        else if (customerLocation == "Europe")
        {
            taxRate = 0.20;
        }
        else
        {
            taxRate = 0.15;
        }

        double productPrice = 100.0;
        double totalTax = productPrice * taxRate;
        double totalPrice = productPrice + totalTax;

        string invoiceContent = $@"
            <h1>Invoice</h1>
            <p>Product Price: ${productPrice}</p>
            <p>Tax Rate: {taxRate * 100}%</p>
            <p>Total Tax: ${totalTax}</p>
            <p>Total Price: ${totalPrice}</p>
        ";

        // Render the HTML content to a PDF document using IronPDF
        var pdf = new ChromePdfRenderer();
        var document = pdf.RenderHtmlAsPdf(invoiceContent);
        document.SaveAs("Invoice.pdf"); // Save the PDF file locally
    }
}

using System;
using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        string customerLocation = "Europe";
        double taxRate;

        // Determine tax rate based on customer location
        if (customerLocation == "USA")
        {
            taxRate = 0.07;
        }
        else if (customerLocation == "Europe")
        {
            taxRate = 0.20;
        }
        else
        {
            taxRate = 0.15;
        }

        double productPrice = 100.0;
        double totalTax = productPrice * taxRate;
        double totalPrice = productPrice + totalTax;

        string invoiceContent = $@"
            <h1>Invoice</h1>
            <p>Product Price: ${productPrice}</p>
            <p>Tax Rate: {taxRate * 100}%</p>
            <p>Total Tax: ${totalTax}</p>
            <p>Total Price: ${totalPrice}</p>
        ";

        // Render the HTML content to a PDF document using IronPDF
        var pdf = new ChromePdfRenderer();
        var document = pdf.RenderHtmlAsPdf(invoiceContent);
        document.SaveAs("Invoice.pdf"); // Save the PDF file locally
    }
}

In this code example, we use an if-else statement to determine the appropriate tax rate based on the customer's location. We create the PDF invoice from HTML string using IronPDF. In C#, we can utilize a C# List to store and manipulate items, such as product prices.

Conclusion

Throughout this tutorial, we've covered the fundamentals of the C# if-else statement, explored various conditional and logical operators, and examined real-life examples to better understand the concept. We even demonstrated a practical application using the powerful IronPDF library, which offers a free trial and licensing options.

Remember, practice is crucial when it comes to mastering programming concepts. Keep experimenting with different scenarios, applying your newfound knowledge of if-else statements and other related concepts.