syntax - How are if statements in C syntactically unambiguous? -

i don't know whole lot c, understand basics , far can tell:

int main() {   if (1 == 1) printf("hello world!\n");   return 0; } 

and

int main() {   if (1 == 1)      printf("hello world!\n");   return 0; } 

and

int main() {   if (1 == 1) {     printf("hello world!\n");   }   return 0; } 

are precisely syntactically equivalent. statement true; string printed; braces (apparently) optional.

sometimes, here on so, see following:

int main() {   if (1 == 1)     printf("one one\n");   printf("is inside if statement??/who kn0ws\n");   return 0; } 

by power vested in codegolf, have been led believe c whitespace-agnostic; lexical analyser breaks tokens component parts , strips whitespace outside strings.

(i mean, whole reason semicolons-on-every-statement-thing parser can strip \n, \t, literal spaces , still know each statement ends, right??)

so how possible unambiguously parse previous bit of code (or perhaps can come better example of mean), if whitespace disregarded?

if c programmers want write in whitespace-dependent pythonic syntax, why write c, , why taught wherever c taught it's okay write lexically ambiguous (both me, programmer, , computer) statements this?

if (1 == 1)   printf("one one\n"); printf("is inside if statement??/who kn0ws\n"); 

the second printf() should never execute inside if statement.

the reason being previous line ends semicolon, indicates end of if-block execute.

(i mean, whole reason semicolons-on-every-statement-thing parser can strip \n, \t, literal spaces , still know each statement ends, right??)

so how possible unambiguously parse previous bit of code (or perhaps can come better example of mean), if whitespace disregarded?

parsing example:

if (1 == 1) // if - ( , ) - statements (or block) follow, skip whitespace

// no { found -> single statement, scan until ; (outside quotes / comments)

printf("one one\n"); // ; encountered, end of if-block

without braces, 1 statement belongs if-block.

but, said already, it's habit use braces. if later add statement (a quick temporary printf() example), inside block.

special case:

int = 0; while(i++ < 10);     printf("%d", i); 

here printf() execute once. mark ; @ end of while().

in case of empty statement, it's better use:

while(i++ < 10)     ; 

to make intention clear (or, alternative, empty block {} can used well).