无法读取未定义的属性“…”

Question

In the server.js code, i have written, at the beginning :

var callForecastDatas = require(__dirname+"/config/callForecastDatas.js");
var callForecastAdsl = require(__dirname+"/config/callForecastAdsl.js");
var callForecastCable = require(__dirname+"/config/callForecastCable.js");
var callForecastFibre = require(__dirname+"/config/callForecastFibre.js");
var callForecastOthers = require(__dirname+"/config/callForecastOthers.js");
var callForecastOtt = require(__dirname+"/config/callForecastOtt.js");
var callForecastSatellite = require(__dirname+"/config/callForecastSatellite.js");
var callForecasttnt = require(__dirname+"/config/callForecasttnt.js");

Then, in a function, i make a reference to one of the elements :

function getAllDeptsCallForecast(res, queryParams)
{
   //some code
   var callForecastAdsl = callForecastAdsl.callForecastPerHourAndPerDay;
   //some code
}

The structure of the /config/callForecastAdsl.js file is the following :

 module.exports = {
callForecastPerHourAndPerDay:`...some datas...
};

Why i have an error 500 like this (in reference to the line with callForecastAdsl in the function GetAllDeptsCallForecast)?

TypeError: Cannot read property 'callForecastPerHourAndPerDay' of undefined

Answer 1

You're shadowing the variable:

function getAllDeptsCallForecast(res, queryParams)
{
   var callForecastAdsl = callForecastAdsl.callForecastPerHourAndPerDay;
   //  ^^^^--- This is shadowing the imported `callForecastAdsl`
}

That means that the callForecastAdsl from your require isn't available within that function, only its local callForecastAdsl variable, which initially has the value undefined .

Just use a different name:

function getAllDeptsCallForecast(res, queryParams)
{
   var someOtherName = callForecastAdsl.callForecastPerHourAndPerDay;
   //  ^^^^^^^^^^^^^
}