Switch expressions are a feature introduced in C# 8.0 that provide a more concise and expressive way to write switch statements. They allow you to assign values directly to a variable based on the result of evaluating different cases, making code more readable and reducing boilerplate.

Here's a basic explanation of switch expressions and an example:

Traditional Switch Statement:

int day = 3;
string dayName;

switch (day)
{
    case 1:
        dayName = "Monday";
        break;
    case 2:
        dayName = "Tuesday";
        break;
    case 3:
        dayName = "Wednesday";
        break;
    // ... More cases ...
    default:
        dayName = "Unknown";
        break;
}

Switch Expression:

int day = 3;
string dayName = day switch
{
    1 => "Monday",
    2 => "Tuesday",
    3 => "Wednesday",
    _ => "Unknown"
};

In the switch expression:

• day is the value being evaluated.
• => is used to map each case to its corresponding value.
• _ (underscore) is used as the default case. It's equivalent to the default case in a traditional switch statement.

Switch expressions are concise, readable, and offer pattern-matching capabilities, making them a powerful addition to C#. They are particularly useful when you need to assign values to a variable based on different cases, as demonstrated in the example above.