objective c - ObjC: scanf skipped in do/while loop -

-

i'm starting teach myself objective c , have been fooling around simple console based calculator. start i'm asking user operation perform, 2 numbers perform operation on, , print answer after it's calculated.

that part seems work fine - next piece i'm trying implement allow user keep making calculations until decide no longer want to. thinking approach put running of calculator inside do/while loop @ end of checking see if user wants continue via 'y' or 'no' via scanf();, , check see user choose respond with. i'm encountering though @ end of first pass, request input via scanf(); gets ignored , program terminates.

i hoping :) i've done due diligence best via troubleshooting, online research(found on white space issue scanf(); didn't help), , guessing date i've been unsuccessful. below main section of code:

int main (int argc, const char * argv[]) {     nsautoreleasepool * pool = [[nsautoreleasepool alloc] init];       float answer;     char op,repeat;     nslog(@"welcome sexy calculater, (_(_)!!"); //don't mind me being weird      calculater *deskcalc;        deskcalc=[[calculater alloc] init];          {          [deskcalc clear];//clear calc          op =[deskcalc getoperator]; //get +,-,*,or/         [deskcalc getnumbers]; //get 2 numbers          [deskcalc calculate: op];         answer=[deskcalc accumulater];          nslog(@"your answer %f!", answer);           nslog(@"would calculate again(y/n)?");         scanf("%c",&repeat);         //nslog(@"you typed: %c", repeat);      } while (repeat=='y');      [deskcalc release];      [pool drain];     return 0; }

thanks in advance help. if haven't provided enough information apologize! please let me know , i'll more willing provide more. again all!

you want have @ scanf skips every other while loop in c

you need work ensure scanf() read newline that's on stdin after user enter 'y', 'n', or whatever other streams of keys hit before pressing enter.

this other posting seems relevant: why scanf() causing infinite loop in code?


Comments

Post a Comment

Popular posts from this blog

linux - Mailx and Gmail nss config dir -

-
i trying send mail linux command line using mailx command. can send local domain no problem want set mail send gmail account receive mail sent gmail account. after configuring mail.rc so: account gmail { set smtp=smtps://smtp.gmail.com:587 set smtp-auth=login set smtp-auth-user=username@gmail.com set smtp-auth-password=password set ssl-verify=ignore } i error: resolving host smtp.gmail.com . . . done. connecting 74.125.25.109 . . . connected. missing "nss-config-dir" variable. "/home/username/dead.letter" 11/354 . . . message not sent. after looking "nss-config-dir" here , located certn.db , keyn.db files , added mail.rc so: account gmail { set smtp=smtps://smtp.gmail.com:587 set smtp-auth=login set smtp-auth-user=username@gmail.com set smtp-auth-password=password set ssl-verify=ignore set nss-config-dir=/home/user/.mozilla/firefox/location.default } now when try send mail using command: echo "sent gmail account" | mailx -v -a
Read more

c# - Is it possible to remove an existing registration from Autofac container builder? -

-
something along lines: builder.registertype<mytype>().as<itype>(); builder.registertype<mytype2>().as<itype>(); builder.deregistertype<mytype>().as<itype>() var container = builder.build(); var types = container.resolve<ienumerable<itype>>(); assert.istrue(types.count == 1); assert.istrue(types[0].gettype == typeof(mytype2)); scenario: go through bunch of assemblies , go register types want make sure have 1 implementation of given type. need before create container. track on own nice if autofac me bit. this cannot done directly using containerbuilder , unless start on new one. mind you, having first built container should able construct new container filtering away unwanted types , reusing registrations first container. this: ... var container = builder.build(); builder = new containerbuilder(); var components = container.componentregistry.registrations .where(cr => cr.activator.limittype != typ
Read more

php - Mysql PK and FK char(36) vs int(10) -

-
i have read mysql can handle indexes , searches better if tables keys integers rather char(36) uuid's. is worth converting int(10)? note: use 1 server , have have plans use multiple databases concurrently therefore removing 1 of big reasons using uuid. our tables innodb if makes difference. thanks in advance. usually rdbms can handle integer keys pk more efficient, other datatypes. reason how build index column, yes: long dont require string (or other typed) keys, should use integers. however: char(36) , int(10) far away being equal, because int(10) much smaller, char(36). dont know, if require many different keys, should keep in mind. update, complete last paragraph: int(10) 32-bit, char(36) 36 - ^byte^ (= 288-bit). not mean, int consumes less space, means, char(36) has 4 times more different keys.
Read more