Populate Object value with FOR LOOP

Question

I am using node-red to populate a chart using data from PLC. The data comes in as a object, then i convert it to a 2D array 36 items long (the object has 36 elements):

for(var i in pressCurve){
    curveArray.push([i, pressCurve [i]]);

then to get this data onto a chart, I create a new msg.payload object in the format:

msg.payload =[{
    "series": ["title 1", "title2"...],
    "data": [[{Array of objects}]],
    "labels": ["label1", "label2"...];

populating the "data" value as my array of objects via hardcoding is easy:

msg.payload = [{
    "series": ["Curve"],
    "data": [
        [{"x": 10, "y": curveArray[0][1]},
        {"x":  20, "y": curveArray[1][1]},
        {"x":  30, "y": curveArray[2][1]},
        {"x":  40, "y": curveArray[3][1]},
        {"x":  50, "y": curveArray[4][1]},
        {"x":  60, "y": curveArray[5][1]},
        {"x":  70, "y": curveArray[6][1]},
        {"x":  80, "y": curveArray[7][1]},
        {"x":  90, "y": curveArray[8][1]},
        {"x": 100, "y": curveArray[9][1]},
        {"x": 110, "y": curveArray[10][1]},
        {"x": 120, "y": curveArray[11][1]},
        {"x": 130, "y": curveArray[12][1]},
        {"x": 140, "y": curveArray[13][1]},
        {"x": 150, "y": curveArray[14][1]},
        {"x": 160, "y": curveArray[15][1]},
        {"x": 170, "y": curveArray[16][1]},
        {"x": 180, "y": curveArray[17][1]},
        {"x": 190, "y": curveArray[18][1]},
        {"x": 200, "y": curveArray[19][1]},
        {"x": 210, "y": curveArray[20][1]},
        {"x": 220, "y": curveArray[21][1]},
        {"x": 230, "y": curveArray[22][1]},
        {"x": 240, "y": curveArray[23][1]},
        {"x": 250, "y": curveArray[24][1]},
        {"x": 260, "y": curveArray[25][1]},
        {"x": 270, "y": curveArray[26][1]},
        {"x": 280, "y": curveArray[27][1]},
        {"x": 290, "y": curveArray[28][1]},
        {"x": 300, "y": curveArray[29][1]},
        {"x": 310, "y": curveArray[30][1]},
        {"x": 320, "y": curveArray[31][1]},
        {"x": 330, "y": curveArray[32][1]},
        {"x": 340, "y": curveArray[33][1]},
        {"x": 350, "y": curveArray[34][1]},
        {"x": 360, "y": curveArray[35][1]}]],
"labels": ["Curve"]
}]

However, i need to do this for 9 different channels of data, so that is a huge amount of redundant code.

What i'd like to do is something like,

msg.payload = [{
    "series": ["Curve"],
    "data": [for(var j = 0; j < 36; j++)){
           var c = 10;
           [{"x" : c, "y": curveArray[i][1]},
           c = c + 10;
             ]],

to loop through each element in the array, and populate the "data" object property in the format above.

I can't seem to be able to use var inside the object property. Is this possible to do?

Answer 1

You can try this :

msg.payload =[{
    "series": ["Cruve"],
    "data": pressCurve.map((element, i) => ({ x: i, y: element }) ),
    "labels": ["Curbe Label"]
}];

Can you share the array of data that you use to fill "series" and "labels" I think my code can be completed ;)