How do I prompt for a variable in one script and use it in another

My first script which prompts the user is as follows

%this main script calls to one main function(isPalindrome) with a subfunction(removeNonAlpha) 
%this script prompts the user for a character vector to test for being a
% palindrome
fprintf('A palindrome is a word, phrase, or sequence that reads the same backward as forward\n')
str=input('Enter text to test for palindrome:','s');
welp=isPalindrome;
if welp==1
    fprintf('Heyy!!  %s  is a palindrome :) ',str)
else
    fprintf('Dang :(  %s  is not a palindrome ',str)
end

The function that the first script calls is as follows

%this function tests whether a character vector is a palindrome
function Welp=isPalindrome(~)
strrevised=removeNonAlpha(str);
if strrevised==fliplr(strrevised)
    Welp=1;    
else
    Welp=0;
end
end
function strrevised=removeNonAlpha(str)
%this function takes in a string and revises it to remove blanks and to
%remove numbers ie take only alpha characters
str2=isletter(str);
strrevised=str(str2);
end

when I run my program i get the error "unrecognized function or variable 'str' "

how can i make it recognize the first variable in the function the script calls

second question (kind of)how can I make welp=1 if my character vector is blank ie if str=[] because right now it would delete a blank vector because it's not a letter.

PSA sorry this question is a lot lol

[Stephen23]

"how can i make it recognize the first variable in the function the script calls "

Why not simply pass WELP as an input argument, just as the MATLAB documentation recommends?:

https://www.mathworks.com/help/matlab/matlab_prog/share-data-between-workspaces.html

Answer 1

[Walter Roberson]

After the line

function Welp=isPalindrome(~)

insert

str = evalin('caller', 'str');

or

str = evalin('base', 'str');

Neither of these is recommended. Recommended would be to have used

welp=isPalindrome(str);

with

function Welp=isPalindrome(str)

[Walter Roberson]

For your second question:

change

if strrevised==fliplr(strrevised)

to

if isequal(strrevised, fliplr(strrevised))

Where comparing '' == fliplr('') gives an empty logical result, using isequal() gives 1 (true)

[Will]

the second method works well. thank you, much appreciated :)