MATLAB: The variable … appears to change size on every loop iteration. Consider preallocating.

Question

I've searched and found a lot of answers on this warning but i cant seem to solve it anyway.

Code works to confirm if a word is a palindrome, but i would like to fix the warning.

word='aibohphobia';
L=length(word);
word2=char(1,L)
for n=1:L
    word2(n)=word(L-n+1);
end
strcmp(word,word2)

(warning at word2)

I get that it has to change the array size for every loop iteration and if I'm correct I'm supposed to preallocate it beforehand.

I tried doing this by defining word2 before the for loop with:

word2=zeros(1,L)

word2=strings(1,L)

word2=char(1,L)

but then I just get an array with 0's as output.

Thanks in advance.

Answer 1

word2 = char(zeros(1,L));