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Switch expressions are introduced in Java SE 12, 19 March 2019, as a preview feature. Here a whole switch expression can be used to return a value. There is also a new form of case label, case L-> where the right-hand-side is a single expression. This also prevents fall through and requires that cases are exhaustive.
In such case it is always possible to use a function call, but this can be cumbersome and inelegant. For example, to pass conditionally different values as an argument for a constructor of a field or a base class, it is impossible to use a plain if-else statement; in this case we can use a conditional assignment expression, or a function call ...
Switch statements can allow compiler optimizations, such as lookup tables. In dynamic languages, the cases may not be limited to constant expressions, and might extend to pattern matching, as in the shell script example on the right, where the *) implements the default case as a glob matching any string.
When Kotlin was announced as an official Android development language at Google I/O in May 2017, it became the third language fully supported for Android, after Java and C++. [47] As of 2020, Kotlin is the most widely used language on Android, with Google estimating that 70% of the top 1,000 apps on the Play Store are written in Kotlin. Google ...
λProlog (a logic programming language featuring polymorphic typing, modular programming, and higher-order programming) Oz, and Mozart Programming System cross-platform Oz; Prolog (formulates data and the program evaluation mechanism as a special form of mathematical logic called Horn logic and a general proving mechanism called logical resolution)
The most common example of the correct use of a switch within a loop is an inversion of control such as an event handler. In event handler loops, the sequence of events is not known at compile-time, so the repeated switch is both necessary and correct (see event-driven programming, event loop and event-driven finite state machine).
For example, an election protocol can be implemented such that every process checks the result of compare_and_swap against its own PID (= newval). The winning process finds the compare_and_swap returning the initial non-PID value (e.g., zero). For the losers it will return the winning PID. This is the logic in the Intel Software Manual Vol 2A:
If-then-else flow diagram A nested if–then–else flow diagram. In computer science, conditionals (that is, conditional statements, conditional expressions and conditional constructs) are programming language constructs that perform different computations or actions or return different values depending on the value of a Boolean expression, called a condition.