not all control paths return a value??

[kenneth6]

int Class::function()
{
     if(a>b)
     {
          if(c==1)
          {
               if(d==2)
               {
                    return 2;
               }
               else
               {
                    return 1;
               }
          }
          if(c==2)
          {
               if(d==2)
               {
                    return 2;
               }
               else
               {
                    return 1;
               }
          }
     }
     else if(a<b)
     {
          if(d>=e)
          {
               return -1;
          }
          else
          {
               return -2;
          }
     }
     else
     {
          if(c=1)
          {
               return 0;
          }
     }
}

Q.1
After I run the above codes, [warning C4715: "not all control paths return a value"], what does it mean? how can I solve the problem?

Q.2
And:
"1>LINK : C:\Console\Debu g\Test.exe not found or not built by the last incremental link; performing full link"
What does it mean?

[JosAH]

Q.1
After I run the above codes, [warning C4715: "not all control paths return a value"], what does it mean? how can I solve the problem?

Q.2
And:
"1>LINK : C:\Console\Debu g\Test.exe not found or not built by the last incremental link; performing full link"
What does it mean?

A1: suppose a > b and !(c == 1 || c == 2), your function doesn't return anything.

A2: was that build your first build? If so, ignore the message.

kind regards,

Jos

[kenneth6]

A1: suppose a > b and !(c == 1 || c == 2), your function doesn't return anything.

A2: was that build your first build? If so, ignore the message.

kind regards,

Jos

HEY! thx ~

If i ensure that the function returned and assigned to c must be either 1 or 2, but not others. can I ignore these errors?

[JosAH]

HEY! thx ~

If i ensure that the function returned and assigned to c must be either 1 or 2, but not others. can I ignore these errors?

Sure, if your compiler still generates code for it; otherwise simply add a dummy
return statement:

if (a > b) {
   if (c == 1) { ... }
   if (c == 2) { ... }
   return 0; /* dummy return; not reached */
}
 

kind regards,

Jos

[kenneth6]

Sure, if your compiler still generates code for it; otherwise simply add a dummy
return statement:

if (a > b) {
   if (c == 1) { ... }
   if (c == 2) { ... }
   return 0; /* dummy return; not reached */
}
 

kind regards,

Jos

THanks a lot ! Jos ~ ~

[JosAH]

THanks a lot ! Jos ~ ~

You're welcome of course; if you make sure you can ensure that c == 1 or c ==2
then the following will be fine too:

if (a < b) {
   if (c == 1) { ... }
   else { ... }
}
 

In the else part is is implicitly assumed that c == 2 which you took care of.
This little trick gets rid of that spurious 'return 0' thing at the end.

kind regards,

Jos