Javascript 从数组中向表中添加行标题？

Question

I have a 2d array that populates a table. Is there a way to insert a column all the way to the left?

//function to create the table
function createTable(tableData) {
  var table = document.createElement('table');
  var row = {};
  var cell = {};

  tableData.forEach(function (rowData) {
    row = table.insertRow(-1);
    rowData.forEach(function (cellData) {
      cell = row.insertCell();
      cell.textContent = cellData;
      let cellVal = cellData;
      //make cells different shades of green and red for pos/neg (based on %)
      if (cellVal > 0) {
        cell.style.backgroundColor = '#00e100';
      } else if (cellVal < 0) {
        cell.style.backgroundColor = 'red';
      }
    });
  });
  document.body.appendChild(table);
}
createTable(transpose_array);

I dont want to add values to the table because of the color conditions, Id just like to add headers to each row on the y-axis of the table using values from an array I have.

Image is below:

Answer 1

The forEach() callback gets a second argument containing the array index, you can use this to index into the headings array, and insert that as the first cell in each row.

//function to create the table
function createTable(tableData, row_headings) {
  var table = document.createElement('table');
  var row = {};
  var cell = {};
  
  tableData.forEach(function(rowData, i) {
    row = table.insertRow(-1);
    cell = row.insertCell();
    cell.textContent = row_headings[i];
    rowData.forEach(function(cellData) {
      cell = row.insertCell();
      cell.textContent = cellData;
      let cellVal = cellData;
      //make cells different shades of green and red for pos/neg (based on %)
      if (cellVal > 0) {
        cell.style.backgroundColor = '#00e100';
      } else if (cellVal < 0) {
        cell.style.backgroundColor = 'red';
      }
    });
  });
  document.body.appendChild(table);
}
createTable(transpose_array, price_array);