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Cant access a global variable

I am getting an undefined when I try the post to twitter function. Should the quote_text variable be global and therefore accessible by the quoteTwitter function?
$(document).ready(function () {
loadJSON();
getQuote();
console.log(quote_text);
});
// Declare variables
var json_obj;
var num = 0;
var quote_text = "";
// Display a quote - this method is not perfect since the random number will repeat itself and it appears as if no new quote is delivered
function getQuote(callback) {
var html = "";
num = randNum();
quote_text = json_obj[num].quote;
html += "<strong> " + quote_text + " </strong>";
$("#quote").html(html);
$("#author").html(json_obj[num].author);
};
// Post the current quote on twitter
function quoteTwitter(quote_text){
var tweet = quote_text;
window.open('https://twitter.com/home?status=' +encodeURIComponent(tweet),"_blank");
}

Your function definition includes quote_text as a parameter, so inside the function it's trying to use that instead of the global variable with the same name. You're presumably not passing anything to the function when you call it, so it comes out as undefined.
You can fix this by changing this:
function quoteTwitter(quote_text){
to this:
function quoteTwitter(){
...but it'd probably be better in the long run to pass the correct value in as a parameter, if possible, instead of depending on global variables.

In a custom widget, inside a validation handler of addMethod(), I have a wrong context (this)

I'm creating a custom combobox which uses jQuery validator.
At first they all are gray except the first (it means Country). When I choose 'Slovenská republika' the second combobox is enabled.
They all are instances of a a custom autocomplete combobox widget.
To enable the validation I use this code (which is called within _create: function(){..})
There you can find $.validator.addClassRules(); and $.validator.addMethod(). I also added the appropriate class so it really does something.
_registerCustomValidator: function(){
var uniqueName = this._getUniqueInstanceNameFromThisID(this.id);
var that = this;
console.log(this.id);//this prints 5 unique ids when the page is being loaded
$.validator.addMethod(uniqueName, function(value,element){
if(!that.options.allowOtherValue){
return that.valid;
}
console.log(that.id);//this always prints the ID of the last combobox StreetName
return true;
}, "Error message.");
var o = JSON.parse('{"'+uniqueName+'":"true"}');
$.validator.addClassRules("select-validator", o);
}
//this.id is my own property that I set in _create
Problem: When I change the value of any instance of combobox, it always prints the ID of the last instance StreetName, but it should belong to the one that has been changed.
I thought it might be because of registering $.validator.addMethod("someName",handler) using such a fixed string, so now I pass a uniqueName, but the problem remains.
Therefore the validation of all instances is based on the property allowOtherValue of the last instance.
I don't understand why it behaves so. Does anyone see what might be the problem?
EDIT:
see my comments in the following code
_registerCustomValidator is a custom function within a widget factory.
//somewhere a global var
var InstanceRegistry = [undefined];
//inside a widget factory
_registerCustomValidator: function(){
var i=0;
while(InstanceRegistry[i] !== undefined) ++i;
InstanceRegistry[i] = this.id;
InstanceRegistry[i+1] = undefined;
var ID = i; //here ID,i,InstanceRegistry are correct
$.validator.addMethod(uniqueName, function(value,element){
//here InstanceRegistry contains different values at different positions, so its correct
console.log("ID=="+ID);//ID is always 5 like keeping only the last assiged value.
var that = InstanceRegistry[ID];
if(!that.options.allowOtherValue){
return that.valid;
}
return true;
}, "Error message");
var o = JSON.parse('{"'+uniqueName+'":"true"}');
$.validator.addClassRules("select-validator", o);
}

It looks like a sneaky combination of closure logic and reference logic. The callback in $.validator.addMethod is enclosing a reference to this which will equal the last value of this when $.validator.addMethod. (Or something like that?)
Glancing at your code, it's not clear to me what this is in this context. So I can't really offer a concrete solution. But one solution might be to create some kind of global registry for your thises. Then you could do something along the lines of:
_registerCustomValidator: function(){
var uniqueName = this._getUniqueInstanceNameFromThisID(this.id);
$.validator.addMethod(uniqueName, function(value,element) {
var instance = InstanceRegistry[uniqueName];
if(! instance.options.allowOtherValue){
return instance.valid;
}
return true;
}, "Error message.");
var o = JSON.parse('{"'+uniqueName+'":"true"}');
$.validator.addClassRules("select-validator", o);
}
The registry could be keyed to uniqueName or id, just so long as it is a value getting enclosed in your callback.

Using Javascript code twice

First of all I want to say that I am sorry for not using the Code sample. This is my first time asking on stackoverflow and I found it really confusing.
I have this javascript code which works perfectly, but when I try to duplicate it and change the variable names it doesn't seem to work.
JavaScript
function saveEdits() {
var editElem = document.getElementById("edit");
var userVersion = editElem.innerHTML;
localStorage.userEdits = userVersion;
document.getElementById("update").innerHTML="Edits saved!";
}
function checkEdits() {
if(localStorage.userEdits!=null)
document.getElementById("edit").innerHTML=localStorage.userEdits;
}
the way i tried to edit(im new to javascript i have no idea what i was doing):
JavaScript
<script type="text/javascript">
function saveEditsplus() {
var editElemplus = document.getElementById("editplus");
var userVersionplus = editElemplus.innerHTML;
localStorageplus.userEditsplus = userVersionhtml;
}
function checkEditsplus() {
if(localStorage.userEditsplus!=null)
document.getElementById("editplus").innerHTML=localStorageplus.userEditplus;
}
</script>

in your code, you changed the name of localStorage to localStoragePlus - but localStorage is something provided by your browser (see .
If you change it back to localStorage, it might work again.
For reference, here's the part with the renamed variable:
function saveEditsplus() {
var editElemplus = document.getElementById("editplus");
var userVersionplus = editElemplus.innerHTML;
localStorageplus.userEditsplus = userVersionhtml;
^^^^
}
By the way, you're not using localStorage correctly. If you want to save something across page reloads, you need to call "set" I learned that this is not true. sorry for the confusion. (tutorial)

Yes, looks like you have no idea what the code is doing… localStorage is a browser api, you can't just rename it (like you can't - and didn't - change document or innerHTML).
However, there's no reason to rename any of the variables at all. By using the var declarations, you made them local to each of the functions, so they won't interfere with each other anyway. All you need to change are the references to the element:
function saveEditsplus() {
var editElem = document.getElementById("editplus");
var userVersion = editElem.innerHTML;
localStorage.userEditsplus = userVersion; // no …html suffix, either
// ^^^^^^^^^^^^^ the storage reference is global, though
}
function checkEditsplus() {
if(localStorage.userEditsplus!=null)
document.getElementById("editplus").innerHTML=localStorage.userEditplus;
}
However, even better than copying the code would have been to give these functions parameters - one for the id of the element, one for the property of localStorage that is supposed to be used.

You cannot modify the localStorage (browser api)!
function saveEdits() {
var editElem = document.getElementById("edit");
var userVersion = editElem.innerHTML;
localStorage.userEdits = userVersion;
document.getElementById("update").innerHTML="Edits saved!";
}
function checkEdits() {
if(localStorage.userEdits!=null)
document.getElementById("edit").innerHTML = localStorage.userEdits;
}

JavaScript global variables declaration

The following script works correctly although I need to make few amends. In each function I am getting the values need for the different formulas. However I tend to replicate the same line of code in different functions.
Ex.
function one(){ var v1= document.getElementById('one').value; }
function two(){ var v1= document.getElementById('one').value; }
Full code
I would like to declare all of the variables once and than only use the ones I need for the specific functions. If I declare them right at the top than once they are called they still hold the original value so I need to update that value to the current one if changed of course.

Your code will be very hard to read if you do it like in your fiddle.
Instead do
var myVars;
window.onload=function() {
myVars = {
'list_price': document.getElementById('list_price'),
'negotiated': document.getElementById('negotiated'),
.
.
'lease_payment': document.getElementById('lease_payment')
}
now you can do
var price = myVars.list_price.value;
or perhaps add a function
function getVal(id) {
var val = document.getElementById(id).value;
if (val =="" || isNaN(val)) return 0;
return parsetInt(val,10);
}
now you can do
var price = getVal("list_price");

mplungjan's solution is a great one. If you're at all concerned by your global vars leaking into the window scope, wrap your code in an Immediately Invoked Function Expression to prevent that from happening:
(function(){
// code goes here
}());

There are two ways to go about this:
Update your variable when the value changes
Use a function that always returns the correct value
1) You can add a listener for the change event or the keyup event that changes your global variable:
// save initial value
var val = document.getElementById('one').value;
// update the value when input is changed
addEventListener(document.getElementById('one'), 'change', function() {
val = document.getElementById('one').value;
});
console.log(val);
2) You can use a function that always returns the current value:
var val = function() { return document.getElementById('one').value; };
console.log(val());
2b) If you hate parenthesis, you can define a property that uses the function above as a getter:
Object.defineProperty(window, 'one', {
get : function() { return document.getElementById('one').value; }
});
console.log(one);

Global Variable Not Assigning between Functions

I am writing an extension for Google Chrome in HTML/Javascript. I am trying to use a global variable to pass information between two functions, however even if I assign my variable in one function it hasn't changed when I read it from the other function.
var type = 0; //define global variable
window.onload=function(){onCreated()}; //set onCreated function to run after loading HTML
function onCreated()
{
chrome.history.search({'text': ''},function(historyItems){gotHistory(historyItems)});//search for historyItems and then pass them to the gotHistory function
}
function gotHistory(historyItems)
{
var idcount=0;//used to increment the ids of each new element added
for(var count=0; count < historyItems.length; count++)//go through each history item
{
chrome.history.getVisits({'url':historyItems[count].url}, function(visitItems){gotVisits(visitItems)}); //search for visitItems for the url and pass the results to gotVisists function (atm all this function does is assign the global variable to =3)
var body = document.getElementById("outputid");//find the body of the HTML
var newt = document.createElement("p");//create a new element
newt.setAttribute("id","url"+idcount);//give it a unique id
newt.innerHTML = historyItems[count].title;//set the text to say the title of the url
if(type != 0)//if the other function was successful, type=3 and the text should be green
{
newt.style.color="green";
}
body.appendChild(newt);//add the new element to the body
idcount++;
}
}
function gotVisits(visitItems)
{
//assign the global variable to be 3
type = 3;
}
But, the elements are NEVER green. They should always be green. This means that in the function gotVisits, type is not being successfully assigned to 3.
Can anyone explain what is going on here?
Cheers,
Matt
p.s I realise the gotVisits function is useless here really, but I'm using it to demonstrate a point. In reality I will use it to pass back useful information to

Rather than:
var type = 0;
Try:
window.type = 0;
Optionally you can also use a closure such as:
(function() {
var type = 0;
var type = 0; //define global variable
window.onload=function(){onCreated()}; //set onCreated function to run after loading HTML
function onCreated()
{
chrome.history.search({'text': ''},function(historyItems){gotHistory(historyItems)});//search for historyItems and then pass them to the gotHistory function
}
function gotHistory(historyItems)
{
var idcount=0;//used to increment the ids of each new element added
for(var count=0; count < historyItems.length; count++)//go through each history item
{
chrome.history.getVisits({'url':historyItems[count].url}, function(visitItems){gotVisits(visitItems)}); //search for visitItems for the url and pass the results to gotVisists function (atm all this function does is assign the global variable to =3)
var body = document.getElementById("outputid");//find the body of the HTML
var newt = document.createElement("p");//create a new element
newt.setAttribute("id","url"+idcount);//give it a unique id
newt.innerHTML = historyItems[count].title;//set the text to say the title of the url
if(type != 0)//if the other function was successful, type=3 and the text should be green
{
newt.style.color="green";
}
body.appendChild(newt);//add the new element to the body
idcount++;
}
}
function gotVisits(visitItems)
{
//assign the global variable to be 3
type = 3;
}
})();
This saves you from polluting the window object, which you should avoid doing anyhow and allows the inner functions access to the type variable.
It should do what you want.
Also the outer function wrapper for your window.onload is redundant, just do:
window.onload = onCreated;

It looks like chrome.history.getVisits executes the callback asynchronously, so you first try to check that variable, and it gets updated later. You can verify this with a pair of console.log messages.
Move the rest of the code inside the callback, so it gets executed at the right time.