c - while loop and arithmetic operator -

int = 5;   while(i>5)  printf("%d",i);                 

prints nothing.

int = 5;  while ( 5<i<10 ) { printf("%d",i);                       i++; } 

prints 5

in both cases shouldn't result "prints nothing" . because 5 not less 5.

in c integer used boolean: 0 false, else true. @jonathanleffler noted (see comment below), in c99 , c11 there standard boolean datatype, expands integer constants (0 , 1). link.

when write expression 5 < < 10, treated (5 < i) < 10, 5 < i boolean expression, returns 0. (0) < 10, true, that's why loop's body executed. in order make loop condition correct, shoould use like:

while (5 < && < 10)