Why do I get a \"Jump to case label\" error in my C switch statement, and how can I fix it?

Troubleshooting Switch Statement Jump Label Errors

In C , using switch statements often leads to compile errors like "Jump to case label." This occurs when a variable declared in one case is inadvertently accessed in a subsequent case.

Consider the following code:

<code class="cpp">int main() {
    int choice;
    std::cin >> choice;
    switch (choice) {
      case 1:
        int i = 0;
        break;
      case 2: // error here
    }
}</code>

In this case, the compiler error occurs because the variable i is declared in case 1. However, it is accessible in case 2 even though it is not initialized.

To resolve this, enclose the case label with curly braces { }. This ensures that the variable is only accessible within the scope of the case where it is initialized.

<code class="cpp">int main() {
    int choice;
    std::cin >> choice;
    switch (choice) {
      case 1: {
        int i = 0;
        break;
      }
      case 2:
        break;
    }
}</code>

Essentially, switch statements utilize goto statements to jump to specific cases. If a variable is declared in one case and the statement jumps to another case, the variable still exists but may not be initialized. Using curly braces creates a separate scope for each case, isolating its variables.

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