Page History

A switch block comprises several case labels and an optional but highly recommended default label. By convention, statements that follow each case label end with a break statement, responsible for transferring the control to the end of the switch block. When omitted, the next statement statements in the subsequent case label gets get executed. Because the break statement is optional, its omission produces no compiler warnings. If this behavior is unintentional, it can lead to undesirable control flowscause unexpected control flow.

Noncompliant Code Example

In this noncompliant code example, the case wherein the card is 11 does not have a break statement. As a result, the statements for card = 12 are also executed when card = 11.

int card = 11;

switch (card) {
  /* ... */
  case 11: 
    System.out.println("Jack");
  case 12: 
    System.out.println("Queen"); 
    break;
  case 13: 
    System.out.println("King"); 
    break;
  default: 
    System.out.println("Invalid Card"); 
  break;
}

...

Exceptions

EX1: The last label in a switch statement requires no break. The break statement serves to skip to the end of the switch block, so control flow will continue transfers to statements following the switch block with or without itirrespective of its presence. Conventionally, the last label is the default label.

EX2: In some cases, where control flow is intended When it is required to execute the same code for multiple cases, it is permissible to omit the break statement. However, these instances must be explicitly documented.

...

Risk Assessment

Failure to include break statements leads to may cause unexpected control flow.

...