new to character array

[youtubester]

i need guidelines with searching for a character within a character array from a file. and more importantly, i need to understand the logic behind this a lot better. so any info would be much appreciated.

#include <iostream>
#include <fstream>
#include <string>
#define MAX 50
using namespace std;
int main() 
{
char name[MAX+1];
int getIndex(char[], char);
ifstream myfile("customer.txt", ios::in);
if (myfile.fail())
{
	cerr << "Failed to open the file\n";
	return 1;
}
while (! myfile.eof())
{
myfile.getline(name, sizeof(name));
cout << getIndex(name, 'a') << endl;  // searching for the index of the character “a”
} // while
myfile.close();
return 0;
} // main


int getIndex(char s[], char  what)
{
/*This is where i am stuck. i am suppose to return the character in the variable "what" and return a negative 1 if there is not variable in the character array "s"*/
} 

[fafner]

I think you'll need to pass the arrays length to getIndex as well. You could write to the function like this:

http://pastebin.org/209992

Fafner

[Dufresne]

Your algorithm shall look like

i = 0 ;
while( not at the end of character array)
{
if( array[i] == what ) // If character at position i is equal to what
return i ;
i = i+1;
}
return -1 ; // If charcter not found in the array , return -1

[youtubester]

@fafner, can you write down your code again. it seemed to disappeared. THANKS for both of your help. im getting an understanding of how to do this assignment.

@dufresne- when i use your code, the program displays numbers instead.
this is what i wrote:

int getIndex(char s[], char what)
{
	int i =0;
	while (true)
	{
		if (s[i] == what)
			return i;
			i =i +1;
	}
	return -1;
	

}// getIndex 

[youtubester]

well the problem with that is that ihave to return a -1 if the vairable isnt there. i changed the preivous while statement into while(i <80), and it works but it seems to stop reading when it beings to read the numbers.
the text file goes something like this,

Bob 10300 AZ  1567.00
Bob 10301 NM  10987.00
Bob 10303 NM  6545.00
Bob 10307 AZ  4564.00

for the first line my code returns me a negative one but there is an A there where "AZ" appears but i will try your code and see if it works. i cant atm. thank you again

[fafner]

Haha, I must have done something wrong in pastebin;) The problem with your code is that the while-statement continues even after the end of the array is reached, because the "return i" is only called if the char it is looking for is actually found. Here what I recommend:

int getIndex(char s[], char what, int length) {
	for (int i = 0; i < length; i++) {
		if (s[i] == what) {
			return i;
		}
	}
	return -1;
}

EDIT:
This will return -1 if the char isn't found. Sorry for all the reposting, I made some mistakes in the previous code;)

Fafner

[youtubester]

ahh thanks. it works now. thank you!