Converting char to int

[vnrabbit]

Hi all,

I run into a problem. Please help me out.
I read in a file contains char and int, for example, my data file is

tomato 2 3
potato 4 5
ketchup 6 7

now, after I read the file in, I need to store this data into a structure,

struct mystruct
{
int ID;
int time;
int count;
};

while tomato, potato, ketchup are stored in ID;
2,4,6 are stored in time
3,5,7 are stored in count
My problem is how to convert tomato, potato, and ketchup into type int of int ID. Any help would be appreciated.

[Cshot]

You can't. You can only store 4 characters in an int. You will need to store your strings in a char array.

[vnrabbit]

sorry, I think I stated my problem wrong.
Whenever I read in the data file, if it see tomato then it should be converted into a number and assign to ID.

[Cshot]

So you want IDs associated with certain strings? For example:
tomato = ID#1
potato = ID#2
ketchup = ID#3

Then simply read the field in as a string. Compare it with the words you expect and assign the appropriate values.

struct mystruct a;
char holdsyourstring[LENGTH];
// read string in from file
.
.
.
if(strcmp(holdsyourstring, "tomato") == 0)
   a.ID = 1;

[vnrabbit]

Thank you Cshot.
I also have a question. How can I put 2,4,6 into time and 3,5,7 into count. And if I declare an array like

struct mystruct table[3];

and contain the data from the file read in to this array. Please help me to solve this problem. Thanks a lot!

[Cshot]

The easiest way to do this in your case is using the fscanf function. (Ideally you'd want to use fgets)

i = 0;
// while not end of file
fscanf("%s %d %d", tempString, &table[i].time, &table[i].count);
// find id associated with your string and store in table[i].ID
++i;
// end while

[vnrabbit]

Thank you Cshot. Let me try.

[quzah]

Boooo. Here's the easy fix:

1) Use binary files.
2) Use fread.
3) Be amazed at how easy this was.

Woah. I swear I just typed this exact same thing!

Quzah.

[Cshot]

That works great too. But you need to write a program to generate those files. Not that user friendly if you just wanna go in and type in a few changes.

[vnrabbit]

I used

if(strcmp(holdsyourstring, "tomato") == 0)
a.ID = 1;

and it gives me an error "can't conver 'int' to const char*" and type mismatch. Please tell me why I have this error. Thanks!

[Hammer]

Originally posted by vnrabbit
I used

if(strcmp(holdsyourstring, "tomato") == 0)
a.ID = 1;

and it gives me an error "can't conver 'int' to const char*" and type mismatch. Please tell me why I have this error. Thanks!

Because you're using the wrong variable types.