问题
Consider this code:
class Test
{
public:
Test() { i = 0; }
private:
int i;
};
Data member 'i' is used even before it is declared/defined. Should this not be a compilation error ? (It compiled fine!!!)
回答1:
The rule is that member functions defined in the class definition are compiled as if they were defined immediately after the class definition.
回答2:
No it shouldn't, within the context of the class definition, all members, data members or functions have complete visibility.
回答3:
where is the data member used before declaration?
class Test
{
public:
Test() { i = 0; } // constructor
private:
int i; //datamemeber
};
main()
{
Test obj; // memory allocated only here
}
the constructor is called after only the obj is created in main. then the memory for i is allocated. and the the constructor is called so there is scope and visibility for i
来源：https://stackoverflow.com/questions/9783473/accessibility-of-data-member-in-member-function-before-declaration-of-data-membe