C局部变量地址返回警告

Question

I have this function in C:

static Node* newNode(void* e){
Node n={e,NULL,NULL};
return &n;
}

And while compiling I get the following warning that I would like to understand why it happens:

warning: function returns address of local variable [enabled by default]

What kind of dangers are lurking behind this?

Thank you

Answer 1

Local variables are destroyed when you return from a function. Accessing them after the function returned is undefined behavior, don't do this.

Answer 2

警告是因为变量的作用域是函数的局部变量-一旦返回函数，该变量就不再在作用域中，并且其值是不确定的。