FCC Intermediate Algorithm Scripting

Diff 2 Arrays

function diffArray(arr1, arr2) {
    //create a placeholder array that will contain the resultant values
    var newArray = [];
    //iterate through arr1
    for (var i = 0; i < arr1.length; i++) {
        //if arr2 doesn't contain items in arr1
        if (arr2.indexOf(arr1[i]) === -1) {
            //save it in newArray
            newArray.push(arr1[i]);
        }
    }
    //iterate through arr1
    for (var j = 0; j < arr2.length; j++) {
        //if arr1 doesn't contain items in arr2
        if (arr1.indexOf(arr2[j]) === -1) {
            //save it in newArray
            newArray.push(arr2[j]);
        }
    }
    console.log(newArray);
}

diffArray([1, "calf", 3, "piglet"], [7, "filly"]);