I like @CandiedOrange's answer, but for completeness-sake, there are other ways you can accomplish this, too. You could use a map (sometimes called a hash or dictionary) to map inputs to functions to call. You don't specify a language, but in C++, it would look something like this:
#include <iostream> #include <map> typedef void (*actionFunction)(); void functionA() { std::cout << "a\n"; } void functionB() { std::cout << "b\n"; } int main(int argc, char *argv[]) { std::map<char, actionFunction> functionMap; // <- this is the map of characters to functions functionMap [ 'a' ] = functionA; functionMap [ 'b' ] = functionB; functionMap [ 'a' ](); // <- Calls the function associated with 'a' return 0; }
You can do a similar thing in straight C with an array of records that contain the mapping above:
#include <stdio.h> typedef void (*actionFunction)(); typedef struct functionMap { char index; actionFunction func; } functionMap; void functionA() { printf("a\n"); } void functionB() { printf("b\n"); } int main() { functionMap fMap[] = { // <- here's the map { 'a', functionA }, { 'b', functionB } }; size_t numMaps = sizeof(fMap) / sizeof(fMap [ 0 ]); char someInput = 'a'; for (size_t i = 0; i < numMaps; ++i) { if (fMap [ i ].index == someInput) { fMap [ i ].func(); // <- this calls the function associated with "someInput" break; } } return 0; }
These fall into the broader category of table-driven or data-driven programming.
