I try to read-in 2 values using scanf() in C, but the values the system writes into memory are not equal to my entered values. Here is the code:
double a,b;
printf("--------\n"); //seperate lines
scanf("%ld",&a);
printf("--------\n");
scanf("%ld",&b);
printf("%d %d",a,b);
If I enter 1 and 2, CMD returns a correct, but b = -858993460 Here is what I already tried: using float or int instead of double, using scanf_s, using scanf("%d or %f for %i or %li or %lf or %e or %g ), using fflush(stdin) to clear keyboard buffer, reading in b first, trying like all possible combinations. I found out that there is a problem with the length of double on 32 bit OS, so that you are forced to use scanf("%lf", &f) to read in a double. No matter what I do, second value is always wrong.
I use MS VS express 2012 for Desktop on Windows 7 32 bit OS.
This question is related to
c
scanf
conversion-specifier
Format specifier in printf
should be %f
for doubl
datatypes since float
datatyles eventually convert to double
datatypes inside printf
.
There is no provision to print float
data. Please find the discussion here : Correct format specifier for double in printf
As far as i know %d
means decadic which is number without decimal point. if you want to load double value, use %lf
conversion (long float). for printf your values are wrong for same reason, %d
is used only for integer (and possibly chars if you know what you are doing) numbers.
Example:
double a,b;
printf("--------\n"); //seperate lines
scanf("%lf",&a);
printf("--------\n");
scanf("%lf",&b);
printf("%lf %lf",a,b);
Use this line of code when scanning the second value:
scanf(" %lf", &b);
also replace all %ld with %lf.
It's a problem related with input stream buffer. You can also use fflush(stdin); after the first scanning to clear the input buffer and then the second scanf will work as expected. An alternate way is place a getch(); or getchar(); function after the first scanf line.
Using %lf
will help you in solving this problem.
Use :
scanf("%lf",&doub)
You are using wrong formatting sequence for double
, you should use %lf
instead of %ld
:
double a;
scanf("%lf",&a);
Source: Stackoverflow.com