Platinum Partner
java,groovy

Groovy: Picking a value from a number of options

The Java Zone is brought to you in partnership with ZeroTurnaround. Discover how you can skip the build and redeploy process by using JRebel.

Let’s say you need to define a value based on a number of conditions. If first condition holds true, then the value is X, if second condition holds true then the value is Y and so on. I used to go with a multi-level ternary operator to accomplish that:

def a = 2
def x = ( a == 1 ) ? 'aa' :
( a == 2 ) ? 'bb' :
( a == 3 ) ? 'cc' :
'dd'
assert x == 'bb'

Today @tim_yates has suggested a more debuggable way:

def a = 2
def x = a.with { switch( it ) {
case 1 : return 'aa'
case 2 : return 'bb'
case 3 : return 'cc'
default : return 'dd' }
}
assert x == 'bb'

Thanks, Tim! Will start using it now. This is very close to Scala version, which is even shorter:

val a = 2
val x = a match {
case 1 => "aa"
case 2 => "bb"
case 3 => "cc"
case _ => "dd"
}
assert ( x == "bb" )

 

From http://evgeny-goldin.com/blog/picking-value/

The Java Zone is brought to you in partnership with ZeroTurnaround. Discover how you can skip the build and redeploy process by using JRebel.