What is the "?:" operator used for in Groovy?

Question

Trying to understand this line of Groovy code:

return strat?.descriptor?.displayName ?: "null"

Is the ?: a shorthand if/else? Does this mean if strat?.descriptor?.displayName is not null, print it, or else print null ?

I'm confused because there isn't anything between the ? and : like I would normally expect in an if/else statement.

Answer 1

Just to add some more insight, the "?:" operator is known as the binary operator or commonly referred to as the elvis operator. The following code examples all produce the same results where x evaluates to true according to Groovy Truth

// These three code snippets mean the same thing. 
// If x is true according to groovy truth return x else return y
x ?: y

x ? x : y  // Standard ternary operator.

if (x) {
  return x
} else {
  return y
}

Click here for more info on Elvis Operator