IS Functions for Strings:
There are many functions for strings, that return logical true or false. The function isletter returns the logical true when the character is a letter of the alphabet. The function isspace returns the logical true when the character is a whitespace character. When strings are passed to such functions, they return the logical true or false for each and every element, or, in another words, each and every character.
>> isletter('a')
ans =
1
>> isletter('EK127')
ans =
1 1 0 0 0
>> isspace('a b')
ans =
0 1 0