Code:
for(int i=1;i<23;i++) {
stringholder2[i] = stringholder1[22-i];
}
This sets i to one for the first iteration. Doing so places the first (that is, the last character of the original string) into the second location of the stringholder2.
Avoid the magic numbers. I'd use two variables for the loop control only because I think it looks cleaner (ikr I've gotta be weird for that :P):
Code:
for (int i = 0, j = stringholder1.length - 1; j >= 0; ++i, --j)
{
stringholder2[i] = stringholder1[j];
}
I'd recommend initializing stringholder2 after that of stringholder1 since you can make it sized to stringholder2.length - 1.