How to Check Values in an Array

[DietRichCola]

I have a program in which the user inputs data and it gets stored into an array. However, no two of the same values can be stored in the array.
I have to write a function to check if the value enters already exists in the array. if it does, it'll return true. if it doesn't, return false.

my main code is:
char city;
do {
n++;
cout<<endl<<"Please enter the city code: ";
cin>> city;
city = toupper(city);
while (cityExists (city, name, n)) {
cout<<endl<<"ERROR: city already exists!"<<endl<<endl;
cout<<"Please enter the city code: ";
cin>>city;
city = toupper(city);
}
name[n] = city;

the function cityExists is:
bool cityExists(char city, char name[], int n) {
int i=0;
bool check1= false;
for (i=0; i<=n; i++) {
if (city == 'name[i]'){
check1 = true;
}
else { }
}
return check1;
}


the function also can't differentiate between upper and lower case city codes. like, 'a' is the same as 'A'. that's why the toupper() function is there.

Please help! thanks!

[firedraco]

You know you can't just "add" elements to an array...you need to set a size first, otherwise you will be accessing out of range data which is very bad. If you don't know how much will be put in, use a vector.

[DietRichCola]

well, i want it to add the value in name[i], if it already doesn't exist in say name[i-1] or a previous array value.
there is a set size, but i don't think that's important. the bool function should only check up until n, the number of values entered.

[firedraco]

Well then just use a for loop like you have...it looks fine to me.

[DietRichCola]

it still doesn't work though. it's returning false to the function instead of true if there's another entry.

[Umz]

Whats the initial value of n and where have you declared its type?
Where have you initialized the array and its size?

Is this the full code? Didn't your compiler give you any errors or warnings?

[DietRichCola]

int n=-1;
char name[100];

sorry no, that wasn't the full code, just two functions of it. it's really long otherwise, and that was the only part i was having trouble with.
and no, the compiler didn't give me any errors or warnings..

[Umz]

For the cityExists() function, what value are you puting into name?

I'd say change your cityExist function to return true if value is found i.e.

bool cityExists(char city, char name[], int n) {

   int i = 0;

   for (i=0; i<=n; i++) {
      if (city == name[i]) {
         return true;
      }
      return false;
}