vb.net - Visual Basic - Counting the occurrence of numbers from a random array -

i need use arrays , strings. program should search 1 number user enter (0-9). here code below. uses array random number, , it's testing occurrences each number. it's not working, don't need test every number anyway.

the program must test 1 number user requests. if random number that's generated say.. '7417', , user user has chosen '7', program report there have been 2 sevens. i'm going use textbox 'txtenter' users number search for. can me? thanks!

private sub button1_click(byval sender system.object, byval e system.eventargs) handles button1.click   randomize()   dim arraynum(1) integer   arraynum(0) = int(rnd() * 100000)    lbldisplaynumber.text = arraynum(0)    dim num integer   txtenter.text = num   dim counts = c in num.tostring()                group c group                select digitgroup = new {.count = group.count(),                                              .digit = c, .group = group}                order digitgroup.count descending                select string.format("there {0} number {1}'s found.",                                      digitgroup.count, digitgroup.digit)   dim message = string.join(environment.newline, counts) end sub 

if want use linq, it's short , readable:

dim counts = c in num.tostring()              group c group              select digitgroup = new {.count = group.count(), .digit = c, .group = group }              order digitgroup.count descending              select string.format("there {0} number {1}'s found.",                                    digitgroup.count, digitgroup.digit) dim message = string.join(environment.newline, counts) 

update: here complete sample shows result of entered number , summary:

dim rnd new random() dim randomint = rnd.next(0, 100000) lbldisplaynumber.text = randomint.tostring()  dim num integer if int32.tryparse(txtenter.text, num) andalso num >= 0 andalso num < 10     dim counts = c in randomint.tostring()              group c group              select digitgroup = new {.count = group.count(), .digit = c, .group = group}              order digitgroup.count descending, digitgroup.digit     dim numcount = counts.firstordefault(function(grp) grp.digit.tostring() = num.tostring())     if numcount isnot nothing         dim nummessage = string.format("there {0} number {1}'s found.", numcount.count, num)         messagebox.show(nummessage)     else         messagebox.show("number not contain " & num)     end if     dim summarycount = grp in counts                        select string.format("there {0} number {1}'s found.", grp.count, grp.digit)     dim summarymessage = string.join(environment.newline, summarycount)     messagebox.show("summary:" & environment.newline & summarymessage) else     messagebox.show("please enter number between 0 , 9.") end if