Question

Is there a “groovy” way to sort a collection by a first parameter, and if the first parameter repeats in two or more elements sort it by a second parameter (the second parameter being an array) ?

Example:

edited (Lenght of the sub array is variable):

[1, [1,2,3]]
[1, [4,6]]
[2, [1,2,3,4,5]]
[3, [1,2,3]]
[3, [1,2,4,5]]

Thanks in advance

Answer 1

You can use the .sort if you want to build up a custom sort:

def lis = []

lis << [3, [1,2,4]]
lis << [1, [1,2,3]]
lis << [3, [1,2,3]]
lis << [1, [4,5,6]]
lis << [2, [1,2,3]]

lis.sort{a,b->
    if(a[0]==b[0])
    {
        def aArray = a[1]
        def bArray = b[1]
        for(int i=0;i<aArray.size();i++)
        {
            if(bArray[i])
            {
                if(aArray[i]!=bArray[i])
                {
                    return aArray[i]<=>bArray[i]
                }
            }
            else
            {
                return 1
            }
        }    
        return 0
    }
    else
        return a[0]<=>b[0]
}


lis.each{x->
println x
}

I didn’t really deal well with the case that the lists are different lengths you could improve on that for your apps needs.