Count the number of occurrences of each letter in string

const char *str = "The quick brown fox jumped over the lazy dog.";

int counts[256] = { 0 };
int i;
size_t len = strlen(str);

for (i = 0; i < len; i++) {
counts[(int)(str[i])]++;
}

for (i = 0; i < 256; i++) {
printf(“The %d. character has %d occurrences.\n”, i, counts[i]);
}