fundamental javascript question

Question

I declared a global:

var myClient;

I have a function:

//Contact is a record object that has toString() which prints the name.
function getClient() {
 myClient = new Object();
 debug(input.contact); // This prints properly
 myClient.contact = input.contact;
 debug(myClient.contact); // This prints properly
}

I have another function that is trying to use the same:

function dispatchClient() {
 debug(myClient.contact);
}

And the result I see is undefined. Is something wrong here? (Ignoring the design aspect)

If that is wrong, then how can I pass the state of global between functions? If that is not wrong, then hmm, I may need to dig deeper!

• Quentin: You haven't shown us how you are calling the functions, and you haven't shown us how input is defined.
• Dan D.: javascript is case sensitive i.e. myclient and myClient are different names.
• mellamokb: Are you calling getClient() before you call dispatchClient()? This works fine: jsfiddle.net/f7xbK.
• Kiran: Sorry for the typo. its myClient only.

Answer 1

dispatchClient is probably being called before getClient gets called. At that point, myClient would be still undefined.

• Kiran: If 'input' is destroyed after 'getClient' function ends, would myClient still be valid?
• Imran: If 'input.name' is String or Number, then yes
• Kiran: Thanks, what if it is an object that has sub properties?
• mVChr: Yes, because you're setting the name prop, which I assume is a string and not an object. If you were assigning the whole input object to myClient, or if input.name is an object then it would be a problem because objects are passed by reference.
• sirlark: Agreed, can't think of a reason this wouldn't work unless dispatchClient is called first. If these functions are attached as event handlers then it's entirely possible they are being called in the wrong order. If this is the case, then do a check for a null myClient value in dispatch, and if it is null, call getClient to set it up before doing anything else

Answer 2

myclient and myClient are two different variables.

but code must still work. unless you call dispatchClient before getClient function.

• Kiran: Sorry, not me. Up voted to correct against my spelling mistake

Answer 3

If you are calling getClient() before dispatchClient() *myClient* variable would be undefined.

Other possiblity is the name(case sensitive), in dispatchClient() you are using my*C*lient that is diferent than the global variable my*c*lient.

If possible(depend on your code), create a instance at the beginning:

var myclient = new Object();

Answer 4

Your var is myclient while your using the object later as myClient. Javascript is case sensitive, so these arn't the same variable.