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Fallthrough in 'switch' statement

Reports 'fall-through' in a switch statement.

Fall-through occurs when a series of executable statements after a case label is not guaranteed to transfer control before the next case label. For example, this can happen if the branch is missing a break statement. In that case, control falls through to the statements after that switch label, even though the switch expression is not equal to the value of the fallen-through label. While occasionally intended, this construction is confusing and is often the result of a typo.

This inspection ignores any fall-through commented with a text matching the regex pattern (?i)falls?\s*thro?u.

There is a fix that adds a break to the branch that can fall through to the next branch.

Example:

switch(x) { case (4): if (condition) { System.out.println("3"); // no break here } else { break; } case (6): System.out.println("4"); }

After the quick-fix is applied:

switch(x) { case (4): if (condition) { System.out.println("3"); } else { break; } break; case (6): System.out.println("4"); }

Inspection Details

By default bundled with:

IntelliJ IDEA 2024.1, Qodana for JVM 2024.1,

Can be installed with plugin:

Java, 241.16690

Last modified: 29 April 2024