Switch Statement - Alternatives

Alternatives

• A series of nested if-else conditionals that examine the target one value at a time.
• A lookup table, which contains, as keys, the case values and, as values, the part under the case statement.

(In some languages, only actual data types are allowed as values in the lookup table. In other languages, it is also possible to assign functions as lookup table values, gaining the same flexibility as a real switch statement. See Control table article for more detail on this).

Lua does now support Case/Switch statements: http://lua-users.org/wiki/SwitchStatement . This lookup technique is one way to implement switch statements in the Lua language, which has no built-in switch.

In some cases, lookup tables are more efficient than non-optimized switch statements since many languages can optimize table lookups, whereas switch statements are not optimized unless the range of values is small with few gaps. A non-optimized, non-binary search lookup, however, will almost certainly be slower than either a non-optimized switch or the equivalent multiple if-else statements.

• A control table (that may be implented as a simple lookup table) can also be customized to accommodate multiple conditions on multiple inputs if required and usually exhibits greater 'visual compactness' than an equivalent switch (that can occupy many statements).
• For object-oriented programs, extensive use of polymorphism can be used