Populate cell values from column to blank cells from another column in Excel Office.js

Question

I have a table that a user fills a Base column with values and the following columns might have empty values that I fill with that Base column values:

I did the code to do that logic, loading the columns and rows, modifying them separately and then I want to load them into the sheet just to see if it's correct:

Excel.run(function (context) {

        var currentWorksheet = context.workbook.worksheets.getActiveWorksheet();
        var inputsTable = currentWorksheet.tables.getItem("Inputs");
        var baseValues = inputsTable.columns.getItemAt(1).load("values");    
        var columnsLoad = inputsTable.columns.load("values");
        var rowsLoad = inputsTable.rows.load("values");

        return context.sync()
        .then(function () {

            var rows = rowsLoad.items;
            var columns = columnsLoad.items;

            // Populate base
            for (let i = 2; i < columns.length; i++) {
                for (let j = 1; j < rows.length; j++) {
                    if(columns[i][j] == "")
                        columns[i][j] = baseValues.values[j];                
                }            
            }             
            
            // Write data from table back to the sheet
            currentWorksheet.getRange("A25:A48").values = baseValues.values;
            currentWorksheet.getRange("B25:B48").values = columns[2].values;

            // Sync to update the sheet in Excel
            return context.sync();
        });
    })

I'm failing to do it because the writing test is showing me the data not modified:

When the expected should be this:

What am I doing wrong?

Answer 1

After doing the smart decision to debug this in a Web browser and understanding better how the objects work, I've come up with this solution:

 Excel.run(function (context) {

        var currentWorksheet = context.workbook.worksheets.getActiveWorksheet();
        var inputsTable = currentWorksheet.tables.getItem("Inputs");
        var baseValues = inputsTable.columns.getItemAt(1).load("values");    
        var columnsLoad = inputsTable.columns.load("values");
        var rowsLoad = inputsTable.rows.load("values");

        return context.sync()
        .then(function () {

            var rows = rowsLoad.items;
            var columns = columnsLoad.items.slice();

            // Populate base
            for (let i = 2; i < columns.length; i++) {
                let column = columns[i].values
                for (let j = 1; j < rows.length; j++) {
                    if(column[j][0] == ""){
                        column[j][0] = baseValues.values[j][0];                
                    }
                }            
            }           
            
            console.log(columns[2].values)
            
            // Write data from table back to the sheet
            currentWorksheet.getRange("A25:A46").values = baseValues.values;
            currentWorksheet.getRange("B25:B46").values = columns[2].values;

            // Sync to update the sheet in Excel
            return context.sync();
        });
    })