CODEWITHSUNDEEP
javascriptjqueryknockout.jstypescript
Alberto Montellano
Alberto Montellano

Reputation: 6266

Javascript , Object property is shown as undefined

I have a json response from a service that looks like:

retrievedData:

{
  "35736":{"Id":0, "Name":"car"}
  ,"48973":{"Id":0, "Name":"book"}
  ,"41981":{"Id":0, "Name":"dog"}
}

I want to get properties values using the numeric keys, for example: 

console.log(retrievedData["35736"]);

There is a list of elements that it is iterated. Each element has a "serial" that matches the key property value.

When I use the hardcoded value:

console.log(retrievedData["35736"]);

It displays the correct object, but when I build the key like this:

var a = String('"' + JSON.stringify(element.Serial()) + '"');
console.log(retrievedData[a]);

it returns undefined. 

resultList.forEach(function (element) {
    console.log("retrieved data, Serial:" + element.Serial());
    var a = String('"' + JSON.stringify(element.Serial()) + '"');
    console.log(a);

    console.log(retrievedData[a]);

    console.log(retrievedData["35736"]);
}

What am I doing wrong here?

The output values, console logs:

retrieved data, Serial:35736
v.ts:199 "35736"
v.ts:204 undefined
v.ts:206 Object {Id: 35736, Name: ""....

Any help will be appreciated.

Upvotes: 0

Views: 93

Answers (1)

basarat
basarat

Reputation: 276303

it returns undefined.

Its because you have ('"' + JSON.stringify(element.Serial()) + '"'); The string will be something like ""35736"" not "35736"

Also using String constructor is a very bad practice as its unconventional (e.g. typeof will be different)

Upvotes: 2

Related Questions