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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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