CODEWITHSUNDEEP
javascriptjsonobject
dottedquad
dottedquad

Reputation: 1391

Why is my value of a javascript object undefined?

I keep getting undefined when I attempt to output the objects value via chrome console. Code:

ws.on('message', function(message) {
     var JSONobj = {"cmd":"updatesb","name":"TestName"};
     console.log('JSON Name Value: %s', message.name); //<--does not work
     console.log('JSON Name Value: %s', JSONobj.name); //<----WORKS!!!!
});

The message argument in ws.on passes {"cmd":"updatesb","name":"TestName"} via websocket communication. The first console output is undefined. The second output is TestName. Why is message.name undefined when it should have a value of TestName and how do I get the value from message.name?

Upvotes: 1

Views: 2178

Answers (2)

tmaj
tmaj

Reputation: 35135

Try: 

 message.name = 'xxx';
 console.log('JSON Name Value: %s', message.name);

to see if the message.name succeeds. As others pointed out, message is most likely not what you think.

Try also console.log(message); and examine the output.

Also, it may be that the on handler receives more then just the message so the handler should in fact look like function(something_else, message), but it is hard to know without knowing what ws is.

Upvotes: 0

SLaks
SLaks

Reputation: 888185

It sounds like your message parameter is a string, not an object.

You can parse that string as JSON by calling JSON.parse().

Upvotes: 5

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