WAD (Working As Designed)
>> a = strsplit(' aa bb cc ',' ')
a =
1×5 cell array
{0×0 char} {'aa'} {'bb'} {'cc'} {0×0 char}
>> a = strsplit(strtrim(' aa bb cc '),' ')
a =
1×3 cell array
{'aa'} {'bb'} {'cc'}
>>
The delimiter comes first and last in the original input string -- that there isn't anything before or after is not important to strsplit; it creates a field based on the number of delimited fields in the string, not on the content of those fields.
If you don't want the leading/trailing blanks to be significant, remove them first as shown.
