Programming Forums > Application Development > C++

STLFBr1 · Apr 27th, 2005, 1:47 PM

I'm working on a program that reads in data from a file. I have it read in the data as a string, since the one column of data is an int and the other is a int followed by several words.

Now the first thing that would help out a lot would be if I could simply read in the first number, then read in just the other number instead of having to read in the whole thing (note: there is a tab between the two and the second one is in this type of format: 11_read_and_write (0)) If I could read them in as an array of ints that would solve all my problems but if not I need to later do a comparison with the strings, both comparing the string to an int and then adding 1 to that string that stores an int. Sorry if this is confusing but heres what I'm doing, hopefully it'll help:

(Toggle Plain Text)

 if(store[x][1] == assign[x][0])
                   {
                       if(store[x][0] == 0)
                          assign[x][1]=assign[x][1]+1;
                       else
                           assign[x][2]=assign[x][2]+1;
                   }

Also I've tried atoi but it seems that it can't do it with strings only with char. Thanks a bunch

iignotus · Apr 27th, 2005, 3:04 PM

Maybe stoi or string.c_string atoi? I'm not sure.

Infinite Recursion · Apr 27th, 2005, 3:41 PM

fairly sure the atoi() would work.

Eggbert · Apr 27th, 2005, 3:42 PM

>I have it read in the data as a string
Why? If the format is <int>\t<int><non-int>, you can still take both integers without using a string, then take the rest of the line as a string or simply discard it:

(Toggle Plain Text)

int a[2];

cin>> a[0] >> a[1];
cin.ignore ( numeric_limits<streamsize>::max(), '\n' );

Josef_Stalin · Apr 28th, 2005, 4:37 PM

Wouldn't it just be easier to segregate the number input into ints and the letter inputs into strings from the beginning?

STLFBr1 · Apr 28th, 2005, 8:48 PM

Well see thats what I was trying to do but the second set of info is all attached like so: 11_read_and_write. So I don't know how to just read that number and discard the rest since I don't need it. I tried setting up an array of ints and read until it hits the underscore but that gave me errors for referencing and underscore with an int. Any ideas?

Ooble · Apr 29th, 2005, 11:04 AM

(Toggle Plain Text)

for (int i = 0; (str[i] >= '0') && (str[i] <= '9'); i++)
{
    num_array[i] = str[i] - '0';
}

That should do it.

Apr 27th, 2005, 1:47 PM	#1
STLFBr1 Newbie Join Date: Apr 2005 Posts: 15 Rep Power: 0	String to int I'm working on a program that reads in data from a file. I have it read in the data as a string, since the one column of data is an int and the other is a int followed by several words. Now the first thing that would help out a lot would be if I could simply read in the first number, then read in just the other number instead of having to read in the whole thing (note: there is a tab between the two and the second one is in this type of format: 11_read_and_write (0)) If I could read them in as an array of ints that would solve all my problems but if not I need to later do a comparison with the strings, both comparing the string to an int and then adding 1 to that string that stores an int. Sorry if this is confusing but heres what I'm doing, hopefully it'll help: (Toggle Plain Text) if(store[x][1] == assign[x][0]) { if(store[x][0] == 0) assign[x][1]=assign[x][1]+1; else assign[x][2]=assign[x][2]+1; } if(store[x][1] == assign[x][0]) { if(store[x][0] == 0) assign[x][1]=assign[x][1]+1; else assign[x][2]=assign[x][2]+1; } Also I've tried atoi but it seems that it can't do it with strings only with char. Thanks a bunch

Apr 27th, 2005, 3:41 PM	#3
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,473 Rep Power: 8	fairly sure the atoi() would work. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Apr 27th, 2005, 3:42 PM	#4
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 5	>I have it read in the data as a string Why? If the format is <int>\t<int><non-int>, you can still take both integers without using a string, then take the rest of the line as a string or simply discard it: (Toggle Plain Text) int a[2]; cin>> a[0] >> a[1]; cin.ignore ( numeric_limits<streamsize>::max(), '\n' ); int a[2]; cin>> a[0] >> a[1]; cin.ignore ( numeric_limits<streamsize>::max(), '\n' );

Apr 29th, 2005, 11:04 AM	#7
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	(Toggle Plain Text) for (int i = 0; (str[i] >= '0') && (str[i] <= '9'); i++) { num_array[i] = str[i] - '0'; } for (int i = 0; (str[i] >= '0') && (str[i] <= '9'); i++) { num_array[i] = str[i] - '0'; } That should do it. __________________ Me :: You :: Them

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Apr 28th, 2005, 4:37 PM	#5
Josef_Stalin Programmer Join Date: Apr 2005 Posts: 77 Rep Power: 4	Wouldn't it just be easier to segregate the number input into ints and the letter inputs into strings from the beginning?

Apr 28th, 2005, 8:48 PM	#6
STLFBr1 Newbie Join Date: Apr 2005 Posts: 15 Rep Power: 0	Well see thats what I was trying to do but the second set of info is all attached like so: 11_read_and_write. So I don't know how to just read that number and discard the rest since I don't need it. I tried setting up an array of ints and read until it hits the underscore but that gave me errors for referencing and underscore with an int. Any ideas?

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Programming Forums > Application Development > C++

String to int