Nested Switch Statement
ID |
java.no_nested_switch |
Severity |
high |
Remediation Complexity |
medium |
Remediation Risk |
low |
Remediation Effort |
medium |
Resource |
Code Smell |
Language |
Java |
Tags |
code_smell, control-flow, switch |
Description
Reports a switch statement or expression written inside another switch, at any nesting depth. The inner switch is what gets reported — it is the one to pull out into its own method.
Rationale
A nested switch forces the reader to track two independent selector values and two sets of case labels at once, and a break inside the inner switch reads as if it might fall through to the outer one. The code still runs exactly as written; the cost is entirely in how hard it is to follow.
A switch inside a lambda body, or inside an anonymous or local class body, that itself sits inside an outer switch is not reported: the lambda or class body is a separate unit of code the reader already considers on its own.
switch (region) {
case NORTH:
switch (tier) { // Noncompliant -- two selectors to track at once
case GOLD:
applyDiscount();
break;
default:
break;
}
break;
default:
break;
}Remediation
Move the inner switch into its own method and call it from the case that needs it. Each switch then reads with a single selector in view.
switch (region) {
case NORTH:
applyTierDiscount(tier);
break;
default:
break;
}
private void applyTierDiscount(Tier tier) {
switch (tier) {
case GOLD:
applyDiscount();
break;
default:
break;
}
}