Javascript update a value in an array within an array

Question

I'm using the Flot Chart plugin to construct a bar chart. When the script receives new data, I need it to increase that value by one.

var data = [["A", 0], ["B", 0], ["C", 0], ["D", 0], ["E", 0]]
$.plot("#placeholder", [data], options);
channel.on("data", function (receiveddata) {
    data[receiveddata] = data[receiveddata] + 1
    $.plot("#placeholder", [data], options);
});

Now say the the channel receives "A" as the data, I want to increase by one and so on. My code shows what i've tried and also

data.recieveddata

but nothing is working.

Answer 1

You'd do that with :

data[0][1]++;

the array would now be :

[ ["A", 1], ["B", 0], ["C", 0], ["D", 0], ["E", 0] ]
//^     ^
//|     | 1 in second array
//0 in first array

FIDDLE

To use A as a key, you need an object:

var data = {A:0, B:0, C:0};

data[receiveddata] = 2;