ok. Thanks so much kbwood.
changes in brief then:
"localStorage only saves a string value so you need to convert back to an array before use." REQUIRED I ADD .split(',') The .split('"') evidently turns it back into an array. This was too subtle for me because my alert() value doesn't show any visual difference in the value returned. So I was able to reveal the difference by the use of isArray() after understanding your comment i.e.
$( "b" ).append( "" + $.isArray(arr1) ) wow. jquery is cool.
"You have extra characters in the checkbox title that need to be trimmed before checking the value." REQUIRED I ADD $.trim()
AND THEN i had to get rid of that crazy "localStorage.setItem('key', JSON.stringify(arr))" which was my bad attempt to respond the localStorage string to array. not sure what I was thinking.
thanks for taking the time kbwood. I'd stared at this for hours. sorry to require explicit. I'll keep studying. appreciate your patience very much.
-dave