29. Value types

Now that you know about reference types, let’s talk about value types. The other of the two kinds of types in C#.

When you work with a variable of a value type, you’re working with the actual data. This characteristic is known as ‘value semantics’. When you assign a value type variable to another, the value is copied. Therefore, any changes you make using the new variable don’t affect the value in the original variable.

In C#, value types are the types that hold the data within their own memory allocation. They include all numeric data types (such as int, double, float, decimal, etc), char, bool.

Consider the following example:

int original = 10;
int copy = original;

copy = 20;

Console.WriteLine(original); // Outputs: 10
Console.WriteLine(copy); // Outputs: 20

The below script needs to be able to find the current output cell; this is an easy method to get it.

10

20

In the above code, copy is a copy of original. When we change the copy, the original remains unaffected. This illustrates how value semantics is different from reference semantics.

Remember how we said that when we apply the the equality operator (==) to reference types it checks for reference equality rather than value equality? When we use the == operator with value types, it checks for value equality. This means that == checks whether the two values are equivalent, not whether they refer to the same object, but whether the values are equivalent. Here’s an example using int:

int x = 5;
int y = 5;
Console.WriteLine(x == y);  // Outputs: True

True

In this case, x and y hold the same value, so x == y is true.