groovy inject examples from http://groovy.codehaus.org/groovy-jdk/java/util/Collection.html#inject(U,%20groovy.lang.Closure)

groovy inject

inject

public Object inject(Object initialValue, Closure closure)
 
Iterates through the given Collection, passing in the initial value to the 2-arg closure along with the first item. The result is passed back (injected) into the closure along with the second item. The new result is injected back into the closure along with the third item and so on until the entire collection has been used. Also known as foldLeft in functional parlance. Examples:
assert 1*1*2*3*4 == [1,2,3,4].inject(1) { acc, val -> acc * val }

assert 0+1+2+3+4 == [1,2,3,4].inject(0) { acc, val -> acc + val }

assert 'The quick brown fox' ==
    ['quick', 'brown', 'fox'].inject('The') { acc, val -> acc + ' ' + val }

assert 'bat' ==
    ['rat', 'bat', 'cat'].inject('zzz') { min, next -> next < min ? next : min }

def max = { a, b -> [a, b].max() }
def animals = ['bat', 'rat', 'cat']
assert 'rat' == animals.inject('aaa', max)
Visual representation of the last example above:
   initVal  animals[0]
      v        v
max('aaa',   'bat')  =>  'bat'  animals[1]
                           v       v
                     max('bat',  'rat')  =>  'rat'  animals[2]
                                               v       v
                                         max('rat',  'cat')  =>  'rat'