Having two cases in the same switch statement or branches in the same if structure with the same implementation is at best duplicate code, and at worst a coding error. If the same logic is truly needed for both instances, then they should be combined, for an if structure or one should fall through to the other for a switch.

Noncompliant Code Example

switch (i) {
  case 1:
    doSomething();
    break;
  case 2:
    doSomethingDifferent();
    break;
  case 3:  // Noncompliant; duplicates case 1's implementation
    doSomething();
    break;
  default:
    doTheRest();
}

if (a >= 0 && a < 10) {
  doTheThing();
else if (a >= 10 && a < 20) {
  doTheOtherThing();
}
else if (a >= 20 && a < 50) {
  doTheThing();  // Noncompliant; duplicates first condition
}
else {
  doTheRest();
}

Compliant Solution

switch (i) {
  case 1:
  case 3:
    doSomething();
    break;
  case 2:
    doSomethingDifferent();
    break;
  default:
    doTheRest();
}

if ((a >= 0 && a < 10) || (a >= 20 && a < 50)) {
  doTheThing();
else if (a >= 10 && a < 20) {
  doTheOtherThing();
}
else {
  doTheRest();
}

or

switch (i) {
  case 1:
    doSomething();
    break;
  case 2:
    doSomethingDifferent();
    break;
  case 3:
    doThirdThing();
    break;
  default:
    doTheRest();
}

if (a >= 0 && a < 10) {
  doTheThing();
else if (a >= 10 && a < 20) {
  doTheOtherThing();
}
else if (a >= 20 && a < 50) {
  doTheThirdThing();
}
else {
  doTheRest();
}