A variable is a place where you can store data so that you can use it later in your code. A *global* variable is accessible from every point in your code.
### Block Editor
In the Block Editor, all variables are global. See [Block Editor](/microbit/blocks/editor) for info on creating global variables in a Block Editor script. The following block is used to set (assign) global variable's value:
The block below retrieves (gets) the current value of a global variable:
### Touch Develop
In Touch Develop variables are either [global](/microbit/js/data) or [local](/microbit/reference/variables/var). Variables have a name, a [type](/microbit/js/types), and value:
* the *name* is how you'll refer to the variable
* the *type* refers to the kind of value a variable can store
* the *value* refers to what's stored in the variable
[Global variables](/microbit/js/data) are variables that are available throughout your script. Unlike [local variables](/microbit/reference/variables/var), global variables are accessible across functions and in nested code blocks.
### Create a global variable
To create a new global variable:
1. In the Touch Develop [editor](/microbit/js/editor), click `script` (to the right of the search box).
2. Click `+`**add new**.
3. Click `data->`**data** and then choose a [type](/microbit/js/types).
4. Enter a name for your global variable and click **OK**.
### Set and use a global variable
To use a global variable that you've declared (using steps above):
1. In the Touch Develop [editor](/microbit/js/editor), click `data-> `**data** or `data->` + *variable name*.
2. Click `:=` (assignment).
2. Click on the right-side of `:=` and type or click what you want to store in the variable.
Your code should look something like this:
// global number variable
```
counter = 2
```
// global string variable
```
name2 = "Mike"
```
// global boolean variable
```
bool = true
```
(for info on creating image variables, see [Image](/microbit/reference/image/image))
Once you've defined a variable and set it's initial value, use the variable's name whenever you need what's stored in the variable. For example, the following code gets the value stored in the global `counter` variable and shows it on the screen:
```
basic.showNumber(counter, 100)
```
To change the contents of a variable use the [assignment operator](/microbit/reference/variables/assign) `:=`. The following code increments `counter` by 10:
```
counter = counter + 10
```
### Promote, demote, and extract
To **promote** a local variable to a global variable:
* select the local variable name and click `promote to data`. The [var](/microbit/reference/variables/var) keyword changes to the data symbol `data->`.
To **demote** a global variable to a local variable:
* select the global variable name and click `demote to var`
To **extract** the content of a global variable to a local variable:
* select the global variable name and click `extract to var`
### See your global variables
To see a list of the global variables in your script:
* click `script` (along the top) and scroll down to the **vars** heading
