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();
}
Compliant solution
if param == 1 {
openWindow();
} else if param == 2 {
closeWindow();
} else if param == 3 {
moveWindowToTheBackground();
}
