C Program not ending after inputting string? - c

Question

I am completing a programming exercise and when my program is run, it never executes anything past the input line and never terminates. No errors or warnings are coming up so I'm not sure what is wrong. Any help would be great.
This is the assignment:
Write a function that asks the user to input a telephone number as a string containing a threedigit area code, followed by a seven-digit number. Any other characters will be ignored, and only
the first 10 digits will be considered. Assume that the string has at most 200characters.
If the user does not provide at least 10 digits, an error message should be printed out.
It should report the telephone number in the format [phone]. Note that the user may
choose any input format, yet the program should maintain a consistent output format.
The function should be called phone_fmt. Your executable will be called phone. The function
and main should be in the files phone_fmt.c, phone_fmt.h and phone.c, respectively.
This is my code for phone.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "phone_fmt.h"
int main(){
char numStr[200];
char phoneNum[14];
int i=0;
printf("Enter phone number string up to 200 characters: \n ");
scanf("%s", numStr);
if(strlen(numStr)<10){
printf("Invalid. Entry must be at least 10 characters.\n");
exit(1);
}
while(numStr[i] != '\0' && i<10){
if(numStr[i]>'0' && numStr[i]<'9')
break;
i++;
}
if(i > 10){
printf("Invalid. Not enough digits to complete phone number.\n");
exit(1);
}
phone_fmt(numStr, phoneNum);
printf("Phone number: %s \n", phoneNum);
return 0;
}
code for phone_fmt.c
#include "phone_fmt.h"
void phone_fmt(char *numStr, char *phoneNum){
int i=0;
int j=0;
int c=0;
while(numStr[i] != '\0' && c < 10){
if(j==0){
phoneNum[j]='(';
j++;
}
else if(j==4){
phoneNum[j]=')';
j++;
}
else if(j==8){
phoneNum[j]='-';
j++;
}
if(numStr[i] >= '0' && numStr[i] <= '9'){
phoneNum[j]=numStr[i];
j++;
}
}
}
code for phone_fmt.h
#include<stdio.h>
void phone_fmt(char *numStr, char *phoneNum);
Any help would be GREATLY appreciated.

Answer 1

Based on your logic, you need to create a char or int array to hold your 10 phone digit number as your first parameter in phone_fmt() function. The worked code is following.
#include <stdio.h>
void phone_fmt(int *digits, char *phoneNum){
sprintf(phoneNum, "(%d%d%d) %d%d%d-%d%d%d%d", digits[0],
digits[1],
digits[2],
digits[3],
digits[4],
digits[5],
digits[6],
digits[7],
digits[8],
digits[9]);
}
int main(){
char output[20];
int digits[10];
char c;
int i = 0, j = 0;
printf("Enter phone number string up to 200 characters: \n ");
while( (c = getchar()) != '\n' && i < 10 ){
if( (c >= '0' && c <= '9') ){
digits[i++] = (int)(c - '0');
}
++j;
}
if( j < 10 || j > 200 ){
printf("Invalid. Entry must be at least 10 characters and less then 200 characters.\n");
return -1;
}
if(i < 10){
printf("Invalid. Not enough digits to complete phone number.\n");
return -1;
}
phone_fmt(digits, output);
printf("Phone number: %s \n", output);
return 0;
}