How does this C copy function exit its loop?

Question

void copy (char *source, char *dest) {
    while (*dest++ = *source++);
}

The char that is represented by *source is copied to the field <

Answer 1

chars are integral types. Integral types are interpreted as conditionals in the following way:

 0 -> false
 Anything else -> true

Since "strings" in C are null-terminated (meaning 0 or '\0') when it reaches the end of the string it stops.