I can only think that int_j should be explicitly assigned a value at declaration, before actual use in case int_i is passed unassigned, hence : private integer inc(integer int_i) { integer int_j=0; int_j=int_i+1; return int_j; }

So what is wrong with it? Use of private before a return declaration? I'm unfamiliar with this syntax. In C++, private and public are used in the class declaration, not the function definitions.