Question

This is my code:

var Evalcard =  function(number) {
    if (number == 1) {
        this.name = "Ace";
        this.value = 11;
    }
    else if (number == 11) {
        this.name = "Jack";
        this.value = 10;
    }
    else if (number == 12) {
        this.name = "Queen";
        this.value = 10;
    }
    else if (number == 13) {
        this.name = "King";
        this.value = 10;
    }

    return [this.name,this.value];
}

var Buildmatrix = function(mat,suit) {
    row = [];
    var cardeval = new Evalcard(r);
    for (r = 1;r <= 13;r++) {
        cardeval(r);
        row[r] = [r,cardeval(r)[0],suit,cardeval(r)[1]]
        mat.push(row);
    }

    return row;
}

Is my use of the constructor here correct? can I call an instance of Evalcard() by placing the arguments next to the new object (in this case var cardeval)?

Answer 1

Your “Evalcard()” constructor returns an array. You cannot make a function call to an array; it doesn’t make sense.

I think what you want is just:

function Buildmatrix(mat,suit) {
    var row = [];
    for (var r = 1;r <= 13;r++) {
        var nameval = new Evalcard(r); // thanks @patrick dw
        row[r] = [r,nameval[0],suit,nameval[1]]
        mat.push(row);
    }

    return row;
}

(Note also that I added back some missing var keywords — don’t forget var!)

Since you’re returning an array anyway, there’s no reason to treat it as a constructor.