MID$
====

Function
--------

**MID$** returns a substring of given length starting at the given
position. It may also be used as a statement.

Syntax
------

| B$=MID$ (A$,X, [Y])
| MID$ (A$,X,[Y]) = C$

Examples
--------

::

   10 A$= "ABCDEFGH"
   20 PRINT MID$ (A$,3,4)

Prints CDEF

Remarks
-------

A$, X or Y may be expressions. If Y is omitted then all characters to
the right of the Xth character are returned.

In the above example:

| ``MID$ (A$,0,3)`` = 'ABC'
| ``MID$ (A$,20,5)`` = null string
| ``MID$ (A$,7)`` = 'GH'

When MID$ is used as a statement in the form:

MID$(A$,X[,Y])=C$

its sets the part of A$ starting at the Xth character with the substring
C$. The optional parameter Y denotes the length of the part of A$ to be
replaced and if omitted defaults to the length of C$.