match

If expressions can be used to check a large number of conditions however, there is an alternative syntax which allows us to perform advanced pattern matching.

A match expression matches on a variable and checks each case, also known as an arm, to see which branch of logic should be performed.

The cases are checked sequentially in the order they are declared, i.e. from top to bottom, and the last arm must ensure that all cases in the pattern are covered otherwise the compiler will not know how to handle an unspecified pattern and will throw an error.

In the following sections we'll look at:

• A primitive case where a single line of code is used in a case
• Expand the first example to use code blocks in the multi line case
• Look at complex pattern matching to demonstrate their utility