PRB: printf() Appears to Print Incorrect Results for Floats

• The C Run-time (CRT), included with: - Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, 6.0ax - Microsoft C for OS/2, versions 5.1, 6.0, 6.0a - Microsoft C/C++ for MS-DOS, version 7.0 - Microsoft Visual C++ for Windows, versions 1.0, 1.50, 1.51, 1.52 - Microsoft Visual C++, 32-bit Edition, versions 1.0, 2.0, 2.1, 4.0, 5.0

SYMPTOMS

The printf() in the sample code below does not print out the correct values; the float is printed with a hexadecimal specifier before the float specifier.

CAUSE

The problem is that a 2-byte format specifier is being used for an 8-byte value.

RESOLUTION

To correct this problem, replace "%x" and "%lx" with "%lx %lx".

MORE INFORMATION

Sample Code

   /* Compile options needed: none
   */

   #include <stdio.h>
   main()
   {
      float flt  = 1.701411e+038;
      double dbl = 1.701411e+038;

      printf("\nFLOAT         %x   %e", flt,flt);
      printf("\nDOUBLE        %lx  %le",dbl,dbl);
   }

   printf("\nFloat  %lx %lx %e",flt,flt);
   printf("\nDouble %lx %lx %le",dbl,dbl);