Parent topic: C API functions
C-Extensions / C API functions

risnull()

Checks whether a variable is null.

Syntax

int risnull(int vtype, char *pcvar);
  1. vtype is an integer corresponding to the data type of the variable.
  2. pcvar is a pointer to the C variable.

Returns

Table 1. Return codes
Code Description
1 The variable does contain a null value.
0 The variable does not contain a null value.

Usage

The vtype must be one of the data type constants defined in fglExt.h.

Parent topic: C API functions