printing the result of multiplication of return of function ( int ) and a float number constant-CodePudding

i have a problem where the function somme_diagonale return the right result when called in main, but as soon as i multiply it to ( 2 / 9 ) and print the result it appears to be 0.

function :

{
    int i, s = 0 ;
    for ( i = 0 ; i < n ; i   )
    {
        s = s   mat [ i ] [ i ] ;
    }
    return s ;
}```

call : 


``` printf("resultat est : %f", ( float ) ( 2 / 9 ) * somme_diagonale ( F ) );```



i have tested that somme_diagonale ( F ) returns 165 ( int ).

can someone help me ?

CodePudding user response：

Hi, in order to have a float value, either the 2 or the 9 must be cast. This, though, must happen before the division is performed. (2/9) produces a result of type int, which only then is cast to float. What you should do is replace that piece of code with of these options (sorry in advance, I'm not a fan of spaces):

(float)2 / 9 * somme_diagonale(F)
2 / (float)9 * somme_diagonale(F)
(float)2 / (float)9 * somme_diagonale(F)