string and mod function help

I'm trying to manipulate different parts of a string e.g. if the 4th number of a string is even then subtract the 5th number from the 6th number im not sure how to do this,so far i have (considering that my string is called c) :

c= input('enter provided code','s')

if (mod(c(4),3))

rvp = c(6)-c(5)

else

rvp= c(5)-c(6)

Answer 1

[Stephen23]

Try converting the input to a numeric vector, it will make your life much easier:

>> vec = input('enter provided code: ','s')-'0'
enter provided code: 123456
vec =
    1   2   3   4   5   6

and to check if a value is even/odd, try using mod like with a value of 2, not 3:

if mod(vec(4),2)
    rvp = vec(6)-vec(5)
else
    rvp = vec(5)-vec(6)
end

produces this result (which is correct as vec(4) is even, so the difference vec(5)-vec(6) is calculated:

rvp = -1