How to use arrays
Create and initialize an array
An array stores a fixed number of same-type elements contiguously. Unspecified initializer elements become zero.
int scores[5] = {90, 82, 75, 88, 0};Calculate its length
In the same scope as an actual array, divide total bytes by one element's bytes. This does not work after the array has decayed to a pointer.
size_t count = sizeof scores / sizeof scores[0];Visit valid indexes
Indexes begin at zero and end at count - 1. Reading or writing past either boundary is undefined behavior.
for (size_t i = 0; i < count; ++i) {
printf("%d\n", scores[i]);
}Pass a pointer and count
Functions receiving arrays need an explicit element count. Validate externally supplied indexes before using them.
if (index < count) {
scores[index] = new_score;
} else {
fprintf(stderr, "Index out of range\n");
}