8、循环
（1）while和do 循环
l Groovy支持Java相同的while和do 循环
x = 0
y = 5
while ( y-- > 0 ) {
x++
}
assert x == 5
x = 0
y = 5
do {
x++
}
while ( --y > 0 )
assert x == 5
（2）for循环
l Groovy的for循环更简单，而且能够和各种类型的数组、集合、Map等一起工作
// iterate over a range
x = 0
for ( i in 0..9 ) {
x += i
}
assert x == 45
// iterate over a list
x = 0
for ( i in [0, 1, 2, 3, 4] ) {
x += i
}
assert x == 10
// iterate over an array
array = (0..4).toArray()
x = 0
for ( i in array ) {
x += i
}
assert x == 10
// iterate over a map
map = ['abc':1, 'def':2, 'xyz':3]
x = 0
for ( e in map ) {
x += e.value
}
assert x == 6
// iterate over values in a map
x = 0
for ( v in map.values() ) {
x += v
}
assert x == 6
// iterate over the characters in a string
text = "abc"
list = []
for (c in text) {
list.add(c)
}
assert list == ["a", "b", "c"]
