How do I determine how many characters are INPUTted?

I'm trying to let the player name the character, but I need to limit it so it doesn't print over other text, as it's a text-based game.

LEN(STRING$)

LEN(STRING$)

Alright. Do you know how I can save the string as an array or something?

How do I save the string? I've been trying for a while and can't figure out how to save and load the name.

You can do this to retrieve the name.

var maxSize=12
var name$

REPEAT

 INPUT "ENTER_NAME",name$
 IF LEN(name$)>=maxSize THEN ? FORMAT("The name can not exceed %d characters ",maxSize)

UNTIL LEN(name$)<maxSize

Here are some functions to load or save strings into an array

 def saveInArray array[],s$
  var i
  for i=0 to len(s$)-1
   push array,asc(s$[i])
  next
  push array,-1
 end

 def loadInArray(array[], pos)
  var s$=""
  var i=pos
  while i<LEN(array) && array[i]!=-1
   inc s$,chr$(array[i])
   inc i
  wend  
  return s$
 end