Swift Fallthrough Statement

In Swift, the switch statement is a powerful tool for handling a range of different cases. It allows you to check the value of a variable against multiple possible cases, and execute code based on the matching case. The fallthrough statement can be used to transfer control to the next case, without checking its condition.

Using Fallthrough in Swift Switch Statements

The fallthrough statement is used in switch statements to transfer control to the next case, without checking the condition of the case. This can be useful in some cases where you want to execute the same code for multiple cases.

Let's see an example of how fallthrough can be used in a switch statement:

1let grade = "B"
2var message = ""
3
4switch grade {
5case "A":
6    message = "Excellent"
7case "B":
8    message = "Good"
9    fallthrough
10case "C":
11    message += " but you can do better"
12default:
13    message = "You need to work harder"
14}
15
16print(message)

In this example, we have a switch statement that checks the value of the grade variable. If the value of grade is "A", the message "Excellent" is assigned to the message variable. If the value of grade is "B", the message "Good" is assigned to message, and the fallthrough statement is used to transfer control to the next case.

In the next case, the condition is not checked, and the code for this case is executed as well. In this example, the code is simply concatenating a string to the message, to provide some additional feedback to the user. The default case is executed if none of the other cases match the value of the variable.

The output of the above code will be: Good but you can do better

As you can see, the fallthrough statement allowed the code in the "C" case to be executed, even though the condition did not match the value of the grade variable.

The fallthrough statement is a powerful tool in Swift, allowing you to transfer control to the next case in a switch statement without checking the condition. This can be useful in some cases where you want to execute the same code for multiple cases. However, it is important to use this statement with care, as it can make your code harder to read and understand.