Groovy Lesson 2:Some interesting method for Number

The GDK ?defines the methods times,upto,downto,and

step. They all take a closure argument. The following shows these methods in action:

times is just for repetition;

upto is for walking a sequence of increasing numbers;

downto is for decreasing numbers;

and step is the general version that walks until?the end value by successively adding a step width.

?

e.g:

?

def store = ''

10.times{

store += 'x'

}

assert store == 'xxxxxxxxxx'

store = ''

1.upto(5) { number ->

store += number

}

assert store == '12345'

store = ''

2.downto(-2) { number ->

store += number + ' '

}

assert store == '2 1 0 -1 -2 '

store = ''

0.step(0.5,0.1 ){ number ->

store += number + ' '

}

assert store == '0 0.1 0.2 0.3 0.4 '