gcc -pedantic -Wall -ansi

for(currentDirection; currentDirection <= endDirection; currentDirection++)

for(; currentDirection <= endDirection; currentDirection++)

for(currentDirection = 0; currentDirection <= endDirection; currentDirection++)

for(currentDirection; currentDirection <= endDirection; currentDirection++)
 // ^^^^^^^^^^^^^^^ Its saying about the above statement.

int i = 10 ;
 i ;   // This statement is valid but has no effect.

int x = 0;
for(x = 0;x < num; x++){}

int x = 0;
for(; x < num; x++){}

int x;
for(x = 0; x < num; x++){}