如何使用javascript在文本框中添加文本框值

Question

I am creating a program using javascript while a clicking of button it will select a seat and change its background color to green and at the same time the button value will be added to the text field and will toggle accordingly and in the same function i am passing a another value ie fare of the bus. Issue:When i click a seat button its fare is adding to the textbox, but if i will click two or more seat button the fare is just added to the textbox but not doing the sum of the fare. and again when i click a selected seat the fare will be deducted from the total fare. Here I am not using jquery. pls can anybody help me?

// Create a variable for the array!
var selectedSeats = new Array();
var selectedFares= new Array();

// Build a function that will update the textfield.
// Call this, whenever the array gets changed!
function updateListOfSelectedSeats() {
    document.getElementById('selectedseat').value = selectedSeats.join(',');
    document.getElementById('selectedfare').value = selectedFares;
}

// Removes a seat from the list of selected seats
function removeSeatFromList(seat,seatFare) {
    for (var i = 0; i < selectedSeats.length; i++) {
        if (selectedSeats[i] == seat) {
            selectedSeats.splice(i, 1);
            updateListOfSelectedSeats();
            removeFareFromList(seatFare);
            break;
        }
    }
}
function removeFareFromList(seatFares) {
  for (var i = 0; i < selectedFares.length; i++) {
    if (selectedFares[i] == seatFares) {
        selectedFares.splice(i, 1);
        updateListOfSelectedSeats();
        break;
    }
  }

}

// Now the function that reacts to clicks on a seat
function setId(id, value,fare) {
    var Seat = document.getElementById(id);

    switch (Seat.style.backgroundImage) {
        case 'url("themes/frontend/images/greenseat.png")':
            // Seat is already selected and needs to be deselected
            Seat.style.backgroundImage = 'url("themes/frontend/images/seat.png")';
            removeSeatFromList(value,fare);
            break;

        case '':
        case 'url("themes/frontend/images/seat.png")':
            // Seat is empty, select it!
            Seat.style.backgroundImage = 'url("themes/frontend/images/greenseat.png")';
            selectedSeats.push(value);
            selectedFares.push(fare);
            updateListOfSelectedSeats();
            break;
    }
}

Answer 1

So if i understand you correctly , the text field for the price is appearing as a comma separated array instead of getting the sum of values , if that's the case what you can do is as follows :

document.getElementById('selectedfare').value = eval(selectedFares.join('+'));

this should get the sum of you selectedFares array .

Hope this helps.