Read/Write excel sheet using ExcelJS

In this post we will understand how we can read/write excel sheet and styles using ExcelJS [javaScript/TypeScript].

We are using node.js / npm package “ExcelJS” to achieve excel operations.

Installation :

Open terminal [Ctrl + `] and enter

npm install exceljs

or

make an entry to the package.json under dependency and run command npm install

Open any JS editor [let’s say VScode], on your local drive, create a file “ExcelJSTest.js” and open the file in VSCode.

Implementation :

Once installed, create an excel sheet “test.xlsx” under your project folder and follow the below basic code for excel operations

var Excel = require('exceljs');

var wb = new Excel.Workbook();

wb.xlsx.readFile("./test.xlsx").then(function(){

    var sh = wb.getWorksheet("Sheet1");
  
    sh.getRow(3).getCell(2).value = 32;
    wb.xlsx.writeFile("./test.xlsx");
    console.log("Row-3 | Cell-2 - "+sh.getRow(3).getCell(2).value);

    console.log(sh.rowCount);
    //Get all the rows data [1st and 2nd column]
    for (i = 1; i <= sh.rowCount; i++) { 
        console.log(sh.getRow(i).getCell(1).value);
        console.log(sh.getRow(i).getCell(2).value);
    }
})

To run the code, on terminal enter

node ExcelJSTest.js

Output

Row-3 | Cell-2 - 32
3
11
12
21
22
31
32

Reference – ExcelJS