convert alphabet to coresponding number by using ASCII

I have question, how to convert alphabet in lowercase to coresponding number by using ASCII. Such as a=1,b=2,c=3...

Answer 1

[Ameer Hamza]

Like this

char2num = @(c) char(c)-96;

Example

>> char2num('a')
ans =
     1
>> char2num('b')
ans =
     2
>> char2num('z')
ans =
    26

Answer 2

[Walter Roberson]

UpperToLower = @(c) char(c-'A'+'a')

Or if you are daring,

UpperToLower = @(c) char(c+32);