MATLAB: Extracting number from a string

extractMATLABstring

How can I extract the number 1 from the string 'M1' ?

Here are two very simple methods:

>> str = 'M1';
>> sscanf(str,'M%d')
ans =  1
>> str(2)-'0'
ans =  1

How about the helpfully named isempty?:

>>isempty('aaa')
ans = 
    0
>>isempty('')
ans = 
    1

Note that because strings are just matrices (of characters), it's the same test you use for matrix emptiness.

The string 'Hello' consists of single characters already:

str = 'Hello';
for k = 1:length(str)
  disp(str(k))
end

So please explain the wanted type and dimensions of the output. 'H' 'E' 'L' 'L' 'O' is not clear enough.