CODEWITHSUNDEEP
javascripthtmlsessionstorage
Pawan
Pawan

Reputation: 32321

Unable to get the value from a JavaScript object

I have created a JSON object and put it under session object.

How can I retrieve the value from the JSON?

This is my program 

var datainsession = {"firstName":"John", "lastName":"Doe"};

var keyname = 'test';

window.sessionStorage.setItem(keyname + '', datainsession);

var val_sess = window.sessionStorage.getItem(keyname);

var firstname = val_sess.firstName;

alert(firstname);

http://jsfiddle.net/5bea0mr2/3/

Could you please tell me how I can retrieve the first name?

Upvotes: 2

Views: 1196

Answers (4)

ergonaut
ergonaut

Reputation: 7057

You need to convert it to a string on setting, and parse it when you get it out. This method only stores a string, but JSON methods can get around that. Eg.

var datainsession = {"firstName":"John", "lastName":"Doe"};

var keyname = 'test';

 window.sessionStorage.setItem(keyname + '', JSON.stringify(datainsession));

 var val_sess = window.sessionStorage.getItem('test');

var obj = JSON.parse(val_sess).firstName;

alert(obj);

Upvotes: 2

War10ck
War10ck

Reputation: 12508

JSON is represented by a string, not an object. It's simply a JavaScript object with string keys. You'll need to use JSON.stringify() and JSON.parse() to convert the JavaScript object.

Try the following:

var datainsession = {
  firstName: "John",
  lastName: "Doe"
};

var keyname = 'test';

window.sessionStorage.setItem(keyname, JSON.stringify(datainsession));

var val_sess = JSON.parse(window.sessionStorage.getItem(keyname));

var firstname = val_sess.firstName;

alert(firstname);

Upvotes: 4

moonwave99
moonwave99

Reputation: 22817

window.sessionStorage.setItem can only store serialised objects.

So you have to serialise it first via JSON.stringify:

window.sessionStorage.setItem(keyname, JSON.stringify(datainsession))

Then to retrieve it via JSON.parse:

var val_sess = window.sessionStorage.getItem(keyname);
var obj = JSON.parse(val_sess);
// obj.firstName is what you need.

Upvotes: 5

James Donnelly
James Donnelly

Reputation: 128791

Session storage can only hold strings, not objects. Your session here ends up holding your object converted to a string ("[Object object]"), and not the object itself.

To get around this we can firstly convert the object to a JSON string using JSON.stringify():

window.sessionStorage.setItem(keyname + '', JSON.stringify(datainsession));
-> '{"firstName":"John","lastName":"Doe"}'

Then when pulling it convert it back to an object by using JSON.parse():

var val_sess = JSON.parse(window.sessionStorage.getItem(keyname));
-> {"firstName":"John","lastName":"Doe"}

Upvotes: 12

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