function declaration after return statement global variable is not overwritten [duplicate]

Answer 1

function bar() {
  foo = 10;  // define global variable named foo
  return;    // the function return value is "undefined"
  function foo() {}   // define a function named "foo" inside bar function, which means `foo = 10` inside function bar() becomes local variable declaration because "foo" is already defined.
}

So the global variable foo is not impacted at all.