for($k='A';$k<=$highestColumn;$k++) If the number of columns is greater than Z, there will be a problem, so the output will not be possible. Z<AA does not hold during comparison.

Question

for($k='A';$k<=$highestColumn;$k )
If the number of columns is greater than Z, there will be a problem, so the output will not be possible, and Z<AA will not hold during comparison

Answer 1

How does $k='A' compare? I do not understand