void strcpy(char *s, char *t)
{
while (*s++ = *t++)
;
}
* is it (*s)++ or *(s++)?
* it is not *++s nor ++*s
*(*s)++
It is concise syntax but very confusing.
Although this may seem cryptic at first sight, the notational convenience is considerable, and the idiom should be mastered, because you will see it frequently in C programs.
void remove_char(char *s, char c) {
size_t i, j;
for (i = j = 0; s[i] != '\0'; i++)
if (s[i] != c)
s[j++] = c;
s[j] = '\0';
}
There are also idioms for stack manipulation using them: "stack[sp++] = pushed" and "popped = stack[--sp]".
C code does a lot of incrementing and decrementing by one, and so having dedicated syntax for it is convenient.
1. prefix incr/decr precedence: "stack[--sp]"
2. postfix incr/decr precedence: "s[j++]"
3. i have no particular preference for the precedence and am just using a shorthand I inherited from my ancestors whose use cases are no longer relevant to me: "i++" in your for loop
My rank speculation is that C programmers get in a habit of #3 and then forget to consider precedence in an expression where it matters.
In any case, it would be interesting to do a scan of github to see how often prefix and suffix incr/decr had to get switched up in a bugfix patch.
This is not one of those beginner -> journeyman -> expert cycles where coincidentally the way you wrote it as a beginner is identical to how an expert writes it but for a very different reason. I'd expect experts are very comfortable writing either { x = k; k += 1; } or { k += 1; x = k; } depending on which they meant and don't feel an itch to re-write these as { x = k++; } and { x = ++k; } respectively.
I'm slightly surprised none of the joke languages add equally frivolous operators. a%% to set a to the remainder after dividing a by 10, or b** to set b as two to the power b or some other silliness.