Confusing C++ global scope issues -

i taking c++ practice test , i'm confused set of access scope , point of declaration related questions. both questions related each other..i know answers..what need proper explanation :

what value of local variable x @ end of main

 int x = 5;  int main(int argc, char** argv)  {     int x = x;     return 0;  } 

ans: undefined

what value of y @ end of main?

    const int x = 5;     int main(int argc, char** argv)     {        int x[x];        int y = sizeof(x) / sizeof(int);        return 0;     } 

answer: 5

from standard: 3.3.1 [basic.scope.pdecl]

the point of declaration name after complete declarator (clause 8) , before initializer (if any), except noted below.

the standard has 2 examples clarify this:

int x = 12; { int x = x; } 

here second x initialized own (indeterminate) value.

[note: nonlocal name remains visible point of declaration of local name hides it. [example:

const int = 2; { int i[i]; } 

declares local array of 2 integers. ]]

these 2 examples cover 2 cases in question.