Return parameters

#include <stdio.h>
 int Fun ( int n-, int S) {// is the number of n-sum of the number, s is the return number, which is the initial value 0
     IF (n-<= 0 ) {
     return  0 ;         // number of parameters is less than or equal to zero, terminates the 
    S = 0 ; 
    } 
    the else {
     for ( int I = 1 ; I <= n-; I ++) // number is not 0, the 1 + 2 + 3 .. . ... 
    S = S + I; 
     return  . 1 ; 
    } 
} 
main ( void ) {
     int A = . 3 , B = 0 ;
    IF (Fun ( 2 , 0 )) 
    the printf ( " % D \ n- ' , B);
     the else 
    the printf ( " Parameter error " ); 
}

The above procedure is just a function is defined, in the main function was carried out calls for b assignment, but did not return, so the result is the initial output value of b 0.

#include <stdio.h>
 int Fun ( int n-, int & S) {
     IF (n-<= 0 ) {
     return  0 ; // number of parameters is less than or equal to zero, terminates the 
    S = 0 ; 
    } 
    the else {
     for ( int I = . 1 ; I <= n-; I ++) // number 0 is not performed. 3 + 2 + .... 1 ... 
    S = S + I; 
     return  . 1 ; 
    } 
} 
main ( void ) {
     int A = . 3 , B = 0 ;
     IF(Fun (A, B)) 
    the printf ( " % D \ n- ' , B);
     the else 
    the printf ( " Parameter error " ); 
}

After the front of the parameter s together with an ampersand, again when the output of the second argument, the result is correct.

 

 I.e.: parameters form b after performing retain their value, the value back to the argument. For not a reference type parameter can be added to achieve & return parameters.