为什么全局变量不会掩盖局部变量（两者具有相同的名称）？

Question

As we all know it's a standard that local variable masks the scope of global variable if both are having same name.

Example:-

int x=10;

int main()

{

#local variable x masks the scope of global variable x in the main function.

int x=5;

printf("%d",x);

}

My question is that, What is the reason behind the standard and why global variable never masks the locals variable?

Answer 1

In simple language, Inner variables mask outer/global variables because we can control them "easily". If global variables were to mask inner variables then there would be no point in declaring inner variables.

You can read more about variable shadowing/masking in this article https://en.wikipedia.org/wiki/Variable_shadowing

This behaviour is always dependent on the name resolution rules of a particular language. Some languages doesn't allow to declare inner variables(same name) in certain blocks like if and switch . You can read more about this here - https://en.wikipedia.org/wiki/Name_resolution_(programming_languages)#Name_masking