Switch 문에서 \'Jump to Case Label\' 오류가 발생하는 이유는 무엇입니까?

<code class="cpp">#include <iostream>
int main() 
{
    int choice;
    std::cin >> choice;
    switch(choice)
    {
      case 1:
        int i=0;
        break;
      case 2: // error here
        // Code relying on the existence of i
    }
}</code>

<code class="cpp">switch(choice)
{
  case 1:
    {
        int i=0;
        break;
    }
  case 2:
    {
        // Use of i only within this block
    }
}</code>

<code class="cpp">int main() {
    if(rand() % 2) // Toss a coin
        goto end;

    int i = 42;

  end:
    // Similar scope and initialization issues as with switch, but with goto
    std::cout << i;
}</code>