c - Function without any return type -

i know there 2 types of functions: void , ones return (int, double, etc). if function declared without return statements? considered void function? example,

myfunction(int value){ ....... } 

a function declared without return type considered returning int. ancient rule going original k&r c, left in language backward compatibility.

integer promotions , conversion of float arguments doubles done functions without prior definition or forward declaration same reason - backward compatibility old code.

it needless relying on these rules new development bad practice. 1 should declare return type explicitly, , forward-declare or define functions before calling them.