Additional Topics > External Development Guide > IDLInternals - Files and Input Output > Output of IDL Variables

# Output of IDL Variables

## IDL_Print() and IDL_PrintF()

The IDL_Print() and IDL_PrintF() functions output the value of IDL_VARIABLEs. IDL_Print() simply outputs to IDL_STDOUT_UNIT, while IDL_PrintF() outputs to a specified unit.

These functions are the implementation of the built-in IDL system procedures PRINT and PRINTF. See “PRINT/PRINTF” (IDL online help) for information on the available arguments and the order in which you must specify them.

void IDL_Print(int argc, IDL_VPTR *argv, char *argk)

void IDL_PrintF(int argc, IDL_VPTR *argv, char *argk)

### argc

The number of arguments to argv.

### argv

IDL_VPTRs of the IDL_VARIABLEs to be output.

### argk

Keywords. Set this argument to NULL `((char *) 0)`.