If expression

If statements are similar as Java's, but you can provide any expression in them. If the provided expression is not a boolean, the Marcel truth will decide if your expression is true or not.

if (a == 1) {
  println("a is 1")
} else if (a == 2) {
  println("a is 2")
} else {
  println("a is not 1 and not 2")
}

if variable declaration

The marcel truth allows you to declare variable in an if condition, and execute the code block if the variable is truthy

if (Something result = fetchSomething()) {
  println("Fetched $result")
}

You can also unbox Optional values such as in the below example

// assuming getOptionalInteger() returns an Optional
if (Integer result = getOptionalInteger()) {
  println(result)
}