A switch and a chain of if/else if statements is evaluated from top to bottom. At most, only one branch will
be executed: the first one with a condition that evaluates to true.
Therefore, duplicating a condition automatically leads to dead code. Usually, this is due to a copy/paste error. At best, it’s simply dead code and
at worst, it’s a bug that is likely to induce further bugs as the code is maintained, and obviously it could lead to unexpected behavior.
Noncompliant code example
if param == 1 {
openWindow()
} else if param == 2 {
closeWindow()
} else if param == 1 { // Noncompliant
moveWindowToTheBackground()
}
switch i {
case 1:
//...
case 3:
//...
case 1: // Noncompliant
//...
default:
// ...
}
Compliant solution
if param == 1 {
openWindow()
} else if param == 2 {
closeWindow()
} else if param == 3 {
moveWindowToTheBackground()
}
switch i {
case 1:
//...
case 3:
//...
default:
// ...
}
