为什么读到的数是undefined啊？

Question

const fs = require('fs');
const xlsx = require('node-xlsx');
const sheets = xlsx.parse('./shiyan.xlsx');
sheets.forEach(function (sheet) {
    const data = sheet['data'];
    let array = [];
    for (let rowID in data) {
        const row = data[rowID];
        array.push(row[3]);
    }
    console.log(array);
});

Answer 1

打印row，在控制台看看row[3]是不是有值的