Thread: how to parse

I need to use arithmetic on monetary values ($20.32, etc.) while using fscanf, but I don't know how to parse $ and the float value separately. Any help please?!?!?!?!

Well, if you KNOW that the dollar sign is always going to be there, you could always read it in as a string, copy everything after the $ into a different string, and then use the atof() function to turn that into a floating point number. But you might want to write a few lines to check and make sure that the $ is actually present.

starX
www.axisoftime.com

i just looked up the atof function, and the example showed that the string had to be in quotes. is it possible to atof the monetary values depsite the number not being in qutes? Thanks

Originally posted by rtransfi
I need to use arithmetic on monetary values ($20.32, etc.) while using fscanf, but I don't know how to parse $ and the float value separately. Any help please?!?!?!?!

The following example uses sscanf, a close relative of fscanf, with a format specifier "$%lf".

Code:

#include<stdio.h>

int main(void)
{
    int i;
    const char *text[4] = { "$20.32", "$15.99", "not a number", "15.49" };
    double value[4], sum = 0.0;
    for ( i = 0; i < 4; ++i )
    {
        printf("text[%d] = \"%s\"", i, text[i]);
        if ( sscanf(text[i], "$%lf", &value[i]) == 1 )
        {
            printf("; value[%d] = %.2lf", i, value[i]);
            sum += value[i];
        }
        else
        {
            fputs(" -- failed to scan", stdout);
        }
        putchar('\n');
    }
    printf("sum = %.2lf (or write as $%.2lf)\n", sum, sum);
    return 0;
}

My output is as follows.

Code:

text[0] = "$20.32"; value[0] = 20.32
text[1] = "$15.99"; value[1] = 15.99
text[2] = "not a number" -- failed to scan
text[3] = "15.49" -- failed to scan
sum = 36.31 (or write as $36.31)

HTH

Unless I'm completely off my rocker (very possible, as I haven't slept in days), you only need quotes for string literals. If you have a pointer to string you won't need the quotes.

starX
www.axisoftime.com