Explain what fallthrough is and how to prevent it.?

Question

What will be an ideal response?

Answer 1

When a switch statement is executed, the value returned by the expression is compared to each case label in the order in which it is encountered. When a matching label is found, its statements are executed. Unlike with the if/else statement, though, execution of a switch statement does not automatically stop after the statements for a particular case label are executed. Instead, by default the switch statement continues evaluating the rest of the case labels in the list, an event known asfallthrough. Generally, though, once a matching case label is found, evaluation of additional case labels is unnecessary. In addition, the fact that statements for multiple case labels can be executed is a common source of bugs in JavaScript. To ensure that your switch statements perform as expected and that fallthrough does not occur, the last statement for each case label should be break;. Abreak statementis a special kind of statement that is used to end the execution of a switch statement. To end a switch statement once it performs its required task, include a break statement at the end of the statements associated with each case label. ?