32-bit signed binary integer

Sample Fortran usage (by Value) C++ function (by Value)

Sample Fortran usage (by Value)	C++ function (by Value)
`INTEGER4 X, Y, CENTRY X = 5 Y = CENTRY((X)) PRINT , 1 'VALUE RETURNED TO FORTRAN:', Y END`	`extern "FORTRAN" { int centry(int); } #include <stdio.h> int centry(int x) { printf("C arg value: %d\n",x); return(x); }`

INTEGER*4 X, Y, CENTRY
X = 5
Y = CENTRY((X))
PRINT *,
1 'VALUE RETURNED TO FORTRAN:', Y
END

extern "FORTRAN"
{ int centry(int); }
#include <stdio.h>
int centry(int x)
{
  printf("C arg value: %d\n",x);
  return(x);
}

Sample Fortran usage C++ function (by Reference)

Sample Fortran usage	C++ function (by Reference)
`INTEGER4 X, Y, CENTRY X = 5 Y = CENTRY(X) PRINT , 1 'VALUE RETURNED TO FORTRAN:', Y END`	`extern "FORTRAN" { int centry(int &); } #include <stdio.h> int centry(int &x) { printf("C int arg value: %d\n",x); return(x); }`

INTEGER*4 X, Y, CENTRY
X = 5
Y = CENTRY(X)
PRINT *,
1 'VALUE RETURNED TO FORTRAN:', Y
END

extern "FORTRAN"
{ int centry(int &); }
#include <stdio.h>
int centry(int &x)
{
  printf("C int arg value: %d\n",x);
  return(x);
}