Splitting a Variable

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October 10th, 2002, 11:29 PM

jakobie

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Splitting a Variable

I know this is going to end up turning into something really simple but...

I have a variable with the year 2002. I need to print it as both 2002 and 02. How can I only print the last two digits of a variable?

Thank you
Jake

October 11th, 2002, 01:26 AM

Scorpions4ever

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Assuming you have the variable in a char array, you can always offset or increment a char pointer by 2 positions something like this:

Code:

char *date = "2002";

printf("Long date is %s\n", date); /* Prints 2002 */

/* Offsetting the pointer by 2 positions. *date still points to 2002 */
printf("Last two digits are %s\n", date+2); /* Prints 02. */ 

/* Increment char pointer by 2 characters */
date += 2; /* Now *date points to "02" */
printf("Last two digits are %s\n", date); /* Prints 02 */

Hope this helps

October 11th, 2002, 08:00 PM

StealthElephant

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well if its not in a character array, you could always just mod the number by 1000

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October 13th, 2002, 10:39 PM

jakobie

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The whole Modulus thing doesn't work if 1999 is put in, you get 999. If you put in 2002 you get 2. How would I offset in C++. I tried strncpy but I got an error. I was trying to do like,

Code:

strncpy(two, four, 2)

thats not the same one, there was a different one where before the amount of characters you could specify on which character to start coping on.

October 13th, 2002, 11:06 PM

StealthElephant

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mod 100

October 14th, 2002, 11:49 AM

jakobie

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I'm thinking the Mod method would be too big of a pain. 100 works but. If the year is 200X you get one number, not the two.

I tried incrementing a char pointer, and well, I got 52 and 51 for 2005 and 1999.

Thanks guys.

October 14th, 2002, 01:20 PM

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Quote:

I tried incrementing a char pointer, and well, I got 52 and 51 for 2005 and 1999.

That's odd. Are you sure you're increasing the pointer, and not something else?

Anyway, here's an example program that generates a random year between 1900 and 2100, and prints it out both long and short:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>


int
main (int argc, char **argv)
{
        int year;
        char s[5];

        srand(time(NULL));

        year = 1900 + rand() % 200;

        /* convert integer to string */
        snprintf(s, sizeof(s), "%4d", year);

        printf("%s\n", s);

        /* skip past the first two digits */
        printf("%s\n", s + 2);
}

Hope this helps.

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