calculating sum of integers

How to find the sum sum of a intiger for examples if i had an input like 123456789 and the sum of it will be 1+2+3+4+5+6+7+8+9. Is there a special function for this?

Answer 1

[KSSV]

n =  123456789; 
iwant = sum(num2str(n) - '0')

[Aldrich Dias]

How to you do if i want to calculate the sum of the first and last digits?

[Adam Danz]

Use the num2str(n)-'0' conversion KSSV showed you and then index the first and last value.

[KSSV]

Do indexing......A(1), A(end) will pick first and last element from array A.

[Aldrich Dias]

hmm i converted it then do I do prod(n)? or prod(n,1:2)?

[Aldrich Dias]

i get it now

thank you