Hidden features of Groovy?

Answer 1

Using the spread operator in method parameters

This is a great help when converting code to data:

def exec(operand1,operand2,Closure op) {
    op.call(operand1,operand2)
}

def addition = {a,b->a+b}
def multiplication = {a,b->a*b}

def instructions = [
     [1,2,addition],
     [2,2,multiplication]
]

instructions.each{instr->
    println exec(*instr)
}

Also helpful is this usage:

String locale="en_GB"

//this invokes new Locale('en','GB')
def enGB=new Locale(*locale.split('_'))