考虑下面的假设程序语言，该程序允许使用全局变量并可以选择静态或动态作用域。
int i ;
program main ()
{
i = 10;
call f();
}
procedure f()
{
int i = 20;
call g ();
}
procedure g ()
{
print i;
}
令x为静态作用域下打印的值，y为动态作用域下打印的值。则x和y为
(A) x = 10，y = 10
(B) x = 20，y = 10
[C) x = 10，y = 20
(D) x = 20，y = 20答案： (C)
说明：静态作用域：
int i ;
program main ()
{
i = 10;
call f();
}
procedure f()
{
int i = 20;
call g ();
}
procedure g ()
{
print i; //as i=20 is scoped only within f() so it will point to global i
}
So, 10 is printed
Dynamic scoping:
int i ;
program main ()
{
i = 10;
call f();
}
procedure f()
{
int i = 20; // here global scoped i is changed
call g ();
}
procedure g ()
{
print i; // global value changed so, i=20 printed
}
这个问题的测验
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