C# Type Conversion

Introduction

If the variable type is known at compile-time, the language is statically typed. And C# is one of those languages. Since C# is a statically typed language, a variable cannot be declared again or assigned a value of a different type once it has been defined and assigned. There is a solution—type Casting. 

When the variable type changes according to our needs, it is called typecasting. 

When the variable of one data type is changed to another data type is known as Type Casting. According to our needs, we can change the type of data. 

We are now moving to the types of conversion.

Recommended Topic, Palindrome in C# and Ienumerable vs Iqueryable.

Types of Conversion

Implicit Conversion

When the conversion is done automatically, it is called an implicit conversion. In this conversion, no data is lost, so it's also the safest conversion. Since this is automatic conversion, no syntax is required. 

In the case of data types, variables are upgraded into the largest data type, which happens to be present in the expression. It happens when the variable on LHS is greater than the variable on RHS.

Let’s understand with the following code.

We'll start as usual with the Hello world string. Then declare an integer. After that, we'll declare a double and in which we'll initialise with the first integer. Here it'll automatically get casted, and then we'll have both variable outputs. Then we'll verify the conversion by checking the type of variable. 

using System; 
public class CodingNinjas
{
    public static void Main(string[] args)
    {
        Console.WriteLine ("Hello World");
        int Test1 = 9;
        // Automatic casting: int to double
        double Test2 = Test1;
        // Produces Output as 9
        Console.WriteLine(Test1);
        // Produces Output as 9
        Console.WriteLine(Test2);      
        // Produces Output as System.Double
        Console.WriteLine(Test2.GetType());   
    }
}

Output - 

Now, we have to move to the next type.

Explicit Conversion

There may be times when the implicit conversion fails. Maybe the conversion fails, or there may be a risk of data loss. Or, due to some complexity, the implicit conversion fails, then explicit conversion is the way. The process of explicit conversion is also called a cast. 

For the explicit conversion, we need to specify the type in which we want to do the casting in parentheses in front of the value or variable to be converted. 

Let’s understand the concept further with the following code:

We'll declare a double variable and then initialise the same. Then we'll explicitly typecast the double variable into the int variable.

using System; 
public class CodingNinjas
{
    public static void Main(string[] args)
    {
      double Test = 199.7;
        int Test1;
       Test1=(int)Test; 
        // Manually casting double to int.
        System.Console.WriteLine(Test1);
    }
}

Output:

It’s time to move to the next method.

Type Conversion methods or using Convert class

There are some built-in commands to convert data explicitly. First of all, we’ll see the code.

We’ll start with the declaration and initialisation of the variables,i.e. Int, double and bool. Then we will typecast the variables using the in-built commands. Int to string and then int to double. Then we’ll change double to int. And at the end bool to string.

using System;
public class CodingNnjas
{
    public static void Main(string[] args)
    {
int East = 10;
double West = 5.25;
bool North = true;
// convert int to string 
Console.WriteLine(Convert.ToString(East));
 // convert int to double  
Console.WriteLine(Convert.ToDouble(East));
 // convert double to int   
Console.WriteLine(Convert.ToInt32(West));
// convert bool to string 
Console.WriteLine(Convert.ToString(North));   
     }
}

Output -

Following are the built-in methods provided by C# for Explicit Type-Conversions:

Let us now discuss some of the frequently asked questions related to the topic.