[Solved]-How can I get the average of the elements of a generic list that meet a criteria?-LINQ,C#

the following is the answer that works for me:

public double averageif<t1,t2>(ienumerable<t1> average_range, ienumerable<t2> criteria_range, func<t2, bool> criteria)
{
    var t1andt2 = average_range.zip(criteria_range, (l, r) => tuple.create<t1, t2>(l, r));      
    return t1andt2.where(x => criteria(x.item2)).average(x => convert.todouble(x.item1));   
}


void main()
{   
    var average_range = new list<string>() {"10.1", "10.1", "0", "0"} ; 
    var criteria_range = new list<bool>() {true, true, false, false };  
    func<bool, bool> criteria = c => c == true;     
    averageif(average_range, criteria_range, criteria).dump();
}

i'd like to recreate a generic version of the excel function averageif

why don't you just use linq?

var average = collection.where(x => x.something)
                        .average(x => x.someproperty);

note that this will throw an exception if there are no matching elements. if you don't want that, you could use:

var average = collection.where(x => x.something)
                        .defaultifempty()
                        .average(x => x.someproperty);

it's not clear why you would want to create a separate method for this.