Scala pattern matching

Scala has very useful, built-in pattern matching. Pattern matching can be used to test for exact and/or partial matches of entire values, parts of objects, you name it.

We can use this sample script for reference:

def matchTest(x: Any): Any = x match { 
  case 7 => "seven" 
  case "two" => 2 
  case _ => "something" 
} 
val isItTwo = matchTest("two") 
val isItTest = matchTest("test") 
val isItSeven = matchTest(7) 

We define a function called matchTest. The matchTest function takes any kind of argument and can return any type of result. (Not sure if that is real-life programming).

The keyword of interest is match. This means the function will walk down the list of choices until it gets a match on to the x value passed and then returns.

As you can see, we have numbers and strings as input and output.

The last case statement is a wildcard, and _ is catchall, meaning that if the code gets that far, it will match any argument.

 

We can see the output as follows: