I want to create a program in C to check for @ and . if typed in by user -


checking email address if user typed in @ , . symbols. how can fix code?

void emailaddress(){      char emailadd[50];      int emailaddl, i;     printf("please enter email address\n");     scanf("%s", emailadd);     emailaddl=strlen(emailadd);     for(i=0; i<=emailaddl; i++){         if(emailadd[i]!='@'){             printf("the entered email address incorrect. please re-enter email address , must contain '@' specifier\n");             emailadd=(int*)calloc(emailadd, sizeof(char));             scanf("%s", emailadd);         }         if(emailadd[i]!='.'){             printf("the entered email address incorrect. please re-enter email address , must contain '.' specifier\n");             emailadd=(int*)calloc(emailadd, sizeof(char));             scanf("%s", emailadd);         }         else             continue;     } }

the major problem code facing not c logical structure of function. if emailadd contains character different @ and/or different . ask new email address. that's not want.

let's structure problem. here want do:

  1. get user input
  2. check if input contains @
  3. if not, ask new input
  4. check if input contains .
  5. if not, aks new input

you don't want once, long user input correct. more precise want . after @ (otherwise email address stack.overflow@so valid.

consider approach implements behaviour defined above:

#include <stdio.h> #include <stdlib.h> #include <string.h>  int main() {     char emailadd[50];     size_t emailaddl;   /* use size_t instead of int */      /* email address first time */     printf("please enter email address\n");     scanf("%s", emailadd);     emailaddl=strlen(emailadd);      /* loop while address has wrong format */     while(1){         /* create flags: 0 character missing, 1 character found */         int at_flag=0;         int dot_flag=0;         emailaddl=strlen(emailadd);          /* loop through char array. have loop 0 array lenght -1*/         for(int i=0; i<emailaddl; i++){    /* can declare variables in loops */              /* if @ has been found, set flag */             if(emailadd[i] == '@'){                 at_flag=1;             }             /* if . has been found , @ has been found earlier, set flag */             if(at_flag && emailadd[i] == '.'){                 dot_flag=1;             }             /* if both flags have been set, can stop searching */             if(at_flag && dot_flag){                 break;             }         }          /* if no @ has been found, ask */         if(!at_flag){             printf("the entered email address incorrect. please re-enter email address , must contain '@' specifier\n");             scanf("%s", emailadd);         /* if @ has been found, no ., ask */         } else if(!dot_flag){             printf("the entered email address incorrect. please re-enter email address , must contain '.' specifier, after '@' specifier\n");             scanf("%s", emailadd);         /* otherwise leave loop */         } else{             printf("everything fine!\n");             break;         }     } }

let's try scenarios:

$ please enter email address $ stack.overflow  $ entered email address incorrect. please re-enter email address , must contain '@' specifier $ stack.overflow@so $ entered email address incorrect. please re-enter email address , must contain '.' specifier, after '@' specifier $ stack.overflow@so.com $ fine!

Comments

Post a Comment

Popular posts from this blog

angular - Ionic slides - dynamically add slides before and after -

hi i'm using ngfor create set of 3 slides while starting in middle i'm guaranteed able slide left or right on start. when slide right can simple listen reachedend , push slide array i'm looping. but have problem adding slide beginning. if same above , use e.g. array.unshift() or spread add item beginning, view think it's on position 0 , snaps view new slide. the code below work animates slide change index 1. slide = [0,1,2] //example loop slidechanged(event) { if(this.slides.isbeginning()){ this.slide = [this.slide[0]-1, ...this.slide]; this.slides.update(); this.slides.slideto(1) } } <ion-slides [initialslide]="1" (ionslidedidchange)="slidechanged($event)"> <ion-slide *ngfor="let item of slide"> <h1>slide {{item}}</h1> </ion-slide> </ion-slides> any appreciated! you can using ionslidenextend , ionslideprevend events slides . please...
Read more

Add a dynamic header in angular 2 http provider -

i have http interceptor built via tutorial https://scotch.io/@kashyapmukkamala/using-http-interceptor-with-angular2 the problem need have dynamic header changes automatically once changes 'mode' in app. service able tell interceptor change header, or have interceptor pull header (which string)from service each request. able throwing away patch method, call http.patch('new header string') set header string. call in service controls 'mode' setting. wondering if there way interceptor pull recent value service each request or if can add method http provider via interceptor? i've tried call service in interceptor each request returns undefined. because creating new instance of service or copying value before service fired , loaded/changed data. i don't want pass header string every http provider call because defeats purpose of having interceptor, id able set once changes or have provider fetch service before makes request. tl;dr : need add autom...
Read more

minify - Minimizing css files -

i want know how css files can minimized. currently, using external sites css minifier compress css files. however, after removing whitespaces, comments, etc, file sizes reduced 10-15%. how frameworks bootstrap manage make minimized versions kilobytes. as example, css is: body { background-color: #ff0; } the reduction goes 28 bytes 22 bytes other css files have lot more characters still smaller this. actually minifying code means it's remove thing code white space characters new line characters comments block delimiters it reduces amount of code has transferred on web , speed site load fastly.but unreadable format.
Read more