How to combine an array in javascript

Question

Hello I want to merge a array based on the unique item in the array.

The object that I have

totalCells = []

In this totalCells array I have several objects like this

totalCells = [
  {
    cellwidth: 15.552999999999999,
    lineNumber: 1
  }, 
  {
    cellwidth: 14,
    lineNumber: 2
  },
  {
    cellwidth: 14.552999999999999,
    lineNumber: 2
  }, 
  {
    cellwidth: 14,
    lineNumber: 1
  }
];

Now I want to make a array where I have combination of array based on the lineNumber.

Like I have a object with lineNumber property and cellWidth collection. Can I do this ?

I can loop through each row and check if the line number is same and then push that cellwidth. Is there any way that I can figure ?

I'm trying to get an output like this.

totalCells = [
{
  lineNumber : 1,
  cells : [15,16,14]
},
{
  lineNumber : 2,
  cells : [17,18,14]
}
]

Answer 1

Do you mean something like this?

var cells = [
{
  cellwidth: 15.552999999999999,
  lineNumber: 1
}, 
{
  cellwidth: 14,
  lineNumber: 2
},
{
  cellwidth: 14.552999999999999,
  lineNumber: 2
}, 
{
  cellwidth: 14,
  lineNumber: 1
}
]

var totalCells = [];
for (var i = 0; i < cells.length; i++) {
    var cell = cells[i];
    if (!totalCells[cell.lineNumber]) {
        // Add object to total cells
        totalCells[cell.lineNumber] = {
            lineNumber: cell.lineNumber,
            cellWidth: []
        }
    }
    // Add cell width to array
    totalCells[cell.lineNumber].cellWidth.push(cell.cellwidth);
}

Answer 2

What about something like this :

totalCells.reduce(function(a, b) {
  if(!a[b.lineNumber]){
    a[b.lineNumber] = {
      lineNumber: b.lineNumber,
      cells: [b.cellwidth]
    }
  }
  else{
    a[b.lineNumber].cells.push(b.cellwidth);
  }
  return a;
}, []);

Hope this helps!

Answer 3

var newCells = [];
for (var i = 0; i < totalCells.length; i++) {
    var lineNumber = totalCells[i].lineNumber;
    if (!newCells[lineNumber]) { // Add new object to result
        newCells[lineNumber] = {
            lineNumber: lineNumber,
            cellWidth: []
        };
    }
    // Add this cellWidth to object
    newcells[lineNumber].cellWidth.push(totalCells[i].cellWidth);
}