Question

I’m struggling with something that shouldn’t be too difficult but I can’t figure it out I have a number of Arrays with different values and I want to find the common values all of the Arrays have, see example below:

        var arrayOne:Array      = ["1","2","3"];
        var arrayTwo:Array      = ["1","2","7"];
        var arrayThree:Array    = ["1","2","9","12"];

        _resultArray = ["1","2"];

Any help is appreciated.

Answer 1

You can do something like:

///Returns common values between to arrays
function getCommonValues(array1:Array, array2:Array):Array
{
    var len1:int = array1.length;
    var len2:int = array2.length;
    var toReturn:Array = new Array();

    for(var i:int = 0; i < len1; i++){
        for(var n:int = 0; n < len2; n++){
            if(array1[i] == array2[n]){
                toReturn.push(array1[i]);
            }
        }
    }
    return toReturn;
}

Then do something like:

var arrayOneAndTwo:Array = getCommonValues(arrayOne,arrayTwo);
var _resultArray:Array = getCommonValues(arrayOneAndTwo,arrayThree);

Optionally you can modify the function to include all three arrays in the comparison, which would be more efficient.

Edit

If you want to process an unknown amount of arrays you can add:

///Returns common values between X number of sub arrays
function getCommonValuesFromSubArrays(papaArray:Array):Array
{
    if(papaArray.length < 2){ return papaArray; }

    var toReturn:Array = papaArray[0];

    for(var a:int = 1; a < papaArray.length; a++){
        toReturn = getCommonValues(toReturn, papaArray[a]);
    }

    return toReturn;
}

Then something like:

var arr1:Array = ["one","two","three","four","five"];
var arr2:Array = ["one","two","five","six"];
var arr3:Array = ["one","two","three","four","five"];
var arr4:Array = ["one","two","three","four","five"];

var bigOlArray:Array = [arr1,arr2,arr3,arr4];

var _results:Array = getCommonValuesFromSubArrays(bigOlArray);