Way to read input from console in C#

The Console.ReadLine() method is the primary way to read input from the console in C#. This method reads a complete line of text from the console and returns it as a string. Since all console input is received as text, you need to convert it to the appropriate data type when working with numbers or other non-string values.

Syntax

Following is the syntax for reading console input −

string input = Console.ReadLine();

For converting string input to other data types −

int number = Convert.ToInt32(input);        // Convert to integer
double value = Convert.ToDouble(input);     // Convert to double
bool flag = Convert.ToBoolean(input);       // Convert to boolean

Reading and Converting Integer Input

The most common scenario involves reading numeric input. Here's how to read and convert string input to an integer −

using System;

class Demo {
    static void Main() {
        Console.Write("Enter an integer: ");
        string input = Console.ReadLine();
        int number = Convert.ToInt32(input);
        Console.WriteLine("You entered: " + number);
        Console.WriteLine("Double the value: " + (number * 2));
    }
}

The output of the above code is −

Enter an integer: 25
You entered: 25
Double the value: 50

Reading Multiple Data Types

You can read and convert different data types from console input as needed −

using System;

class InputExample {
    static void Main() {
        Console.Write("Enter your name: ");
        string name = Console.ReadLine();
        
        Console.Write("Enter your age: ");
        int age = Convert.ToInt32(Console.ReadLine());
        
        Console.Write("Enter your salary: ");
        double salary = Convert.ToDouble(Console.ReadLine());
        
        Console.WriteLine("<br>--- Your Information ---");
        Console.WriteLine("Name: " + name);
        Console.WriteLine("Age: " + age + " years");
        Console.WriteLine("Salary: $" + salary);
    }
}

The output of the above code is −

Enter your name: John Smith
Enter your age: 28
Enter your salary: 45000.50

--- Your Information ---
Name: John Smith
Age: 28 years
Salary: $45000.5

Using Alternative Parsing Methods

Besides Convert methods, you can also use Parse() and TryParse() methods for type conversion −

using System;

class ParseExample {
    static void Main() {
        Console.Write("Enter a number: ");
        string input = Console.ReadLine();
        
        // Using Parse method
        int number1 = int.Parse(input);
        Console.WriteLine("Using Parse: " + number1);
        
        // Using TryParse method (safer)
        if (int.TryParse(input, out int number2)) {
            Console.WriteLine("Using TryParse: " + number2);
            Console.WriteLine("Parsing successful!");
        } else {
            Console.WriteLine("Invalid input format");
        }
    }
}

The output of the above code is −

Enter a number: 42
Using Parse: 42
Using TryParse: 42
Parsing successful!

Comparison of Conversion Methods

Conclusion

The Console.ReadLine() method is essential for reading user input in C# console applications. Always remember to convert the string input to the appropriate data type using methods like Convert.ToInt32(), Parse(), or the safer TryParse() method when working with numeric values.