CodePudding user response:

Can have a look at the parameter pass by value and the difference between the reference
Void the mul (int n) is modified to void the mul (int & amp; n)

CodePudding user response:

The function has no return value, want to use the int the mul (int n)

CodePudding user response:

Not very normal, two mistakes, 1: n the mul is parameter, not a pointer or reference, value cannot be passed out. 2. The printf, no address, you this is the address of print n, not values. (3) change a compiler, for example vs2017, don't use this ancient compilers

CodePudding user response:

Not return a value, that is, a custom function will return the value to return to the main function, so the main function of n or a random value.

The method of modifying:

 int the mul (void) 
{
Int I, n=1; 
For (I=1; i <10; I++) 
N=n * I; 
Return n. 
} 

Int main (void) 
{
int n; 
N=the mul (); 
Printf (" % d \ n ", n);