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Note: This task is fashioned after the action of the [[http://www.softpanorama.org/Scripting/Shellorama/Control_structures/select_statements.shtml Bash select statement]].
=={{header|Java}}==
<lang java5>public static String select(List<String> list, String prompt){
if(list.size() == 0) return "";
Scanner sc = new Scanner(System.in);
String ret = null;
do{
for(int i=0;i<list.size();i++){
System.out.println(i + ": "+list.get(i));
}
System.out.print(prompt);
int index = sc.nextInt();
if(index >= 0 && index < list.size()){
ret = list.get(index);
}
}while(ret == null);
return ret;
}</lang>
=={{header|Python}}==
|
Revision as of 19:05, 3 June 2009
Menu
You are encouraged to solve this task according to the task description, using any language you may know.
You are encouraged to solve this task according to the task description, using any language you may know.
Given a list containing a number of strings of which one is to be selected and a prompt string, create a function that:
- Print a textual menu formatted as an index value followed by its corresponding string for each item in the list.
- Prompt the user to enter a number.
- return the string corresponding to the index number.
The function should reject out-of-range indices by recreating the whole menu before asking again for a number. The function should return an empty string if called with an empty list. For test purposes use the four phrases: 'fee fie', 'huff and puff', 'mirror mirror' and 'tick tock' in a list.
Note: This task is fashioned after the action of the [Bash select statement].
Java
<lang java5>public static String select(List<String> list, String prompt){
if(list.size() == 0) return ""; Scanner sc = new Scanner(System.in); String ret = null; do{ for(int i=0;i<list.size();i++){ System.out.println(i + ": "+list.get(i)); } System.out.print(prompt); int index = sc.nextInt(); if(index >= 0 && index < list.size()){ ret = list.get(index); } }while(ret == null); return ret;
}</lang>
Python
<lang python>def _menu(items):
for indexitem in enumerate(items): print (" %2i) %s" % indexitem)
def _ok(reply, itemcount):
try: n = int(reply) return 0 <= n < itemcount except: return False
def selector(items, prompt):
'Prompt to select an item from the items' if not items: return reply = -1 itemcount = len(items) while not _ok(reply, itemcount): _menu(items) # Use input instead of raw_input for Python 3.x reply = raw_input(prompt).strip() return items[int(reply)]
if __name__ == '__main__':
items = ['fee fie', 'huff and puff', 'mirror mirror', 'tick tock'] item = selector(items, 'Which is from the three pigs: ') print ("You chose: " + item)
</lang>
Sample runs:
0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: -1 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 0 You chose: fee fie >>> ================================ RESTART ================================ >>> 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 4 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 3 You chose: tick tock