switch-statement

问题 I'm new to python, and I'd like to create a switch case where the cases can have intervals as condition, like: switch = { 1..<21: do one stuff, 21...31: do another } How can I achieve this result? 回答1: As it looks like you already tried, the obvious way of implementing a switch structure in Python is using a dictionary. In order to support intervals , you could implement your own dict class: class Switch(dict): def __getitem__(self, item): for key in self.keys(): # iterate over the intervals

问题 I'm new to python, and I'd like to create a switch case where the cases can have intervals as condition, like: switch = { 1..<21: do one stuff, 21...31: do another } How can I achieve this result? 回答1: As it looks like you already tried, the obvious way of implementing a switch structure in Python is using a dictionary. In order to support intervals , you could implement your own dict class: class Switch(dict): def __getitem__(self, item): for key in self.keys(): # iterate over the intervals

问题 Let's see the problem by code: code-1 #include <stdio.h> int main(int argc, char *argv[]) { int a =1; switch (a) { printf("This will never print\n"); case 1: printf(" 1"); break; default: break; } return 0; } Here the printf() statement is never going to execute - see http://codepad.org/PA1quYX3. But code-2 #include <stdio.h> int main(int argc, char *argv[]) { int a = 1; switch (a) { int b; case 1: b = 34; printf("%d", b); break; default: break; } return 0; } Here int b is going to be

问题 Let's see the problem by code: code-1 #include <stdio.h> int main(int argc, char *argv[]) { int a =1; switch (a) { printf("This will never print\n"); case 1: printf(" 1"); break; default: break; } return 0; } Here the printf() statement is never going to execute - see http://codepad.org/PA1quYX3. But code-2 #include <stdio.h> int main(int argc, char *argv[]) { int a = 1; switch (a) { int b; case 1: b = 34; printf("%d", b); break; default: break; } return 0; } Here int b is going to be

问题 Let's see the problem by code: code-1 #include <stdio.h> int main(int argc, char *argv[]) { int a =1; switch (a) { printf("This will never print\n"); case 1: printf(" 1"); break; default: break; } return 0; } Here the printf() statement is never going to execute - see http://codepad.org/PA1quYX3. But code-2 #include <stdio.h> int main(int argc, char *argv[]) { int a = 1; switch (a) { int b; case 1: b = 34; printf("%d", b); break; default: break; } return 0; } Here int b is going to be

来源： https://stackoverflow.com/questions/35949723/using-method-in-switch-case-statements

来源： https://stackoverflow.com/questions/35949723/using-method-in-switch-case-statements

来源： https://stackoverflow.com/questions/6989647/console-readkey-and-switch-statement-using-letters

来源： https://stackoverflow.com/questions/6860525/c-what-is-faster-lookup-in-hashmap-or-switch-statement

来源： https://stackoverflow.com/questions/6860525/c-what-is-faster-lookup-in-hashmap-or-switch-statement