A *String* is a sequence of characters. For the BBC micro:bit, ASCII character codes 32 to 126 are supported; letters, digits, punctuation marks, and a few symbols. All other character codes appear as a ? on the [LED screen](/device/screen).
Use the [var statement](/reference/variables/var) and the [assignment operator](/reference/variables/assign) `:=` to declare a new *local* string variable. Like this:
Use [show string](/reference/basic/show-string) to display a string on the [LED screen](/device/screen). If the string is multiple characters, the string scrolls right to left. The following example displays `Hello world!` on the micro:bit screen:
The first parameter of `show string` specifies the string, and the second parameter specifies the number of milliseconds between scrolling by one LED column - the larger the value, the slower the scroll will be.
Unlike [local variables](/reference/variables/var), global variables are accessible across functions and in nested code blocks. To find out how to declare a global string variable, see [global variables](/js/data).