# PETSC_NULL

standard way of passing in a null or array or pointer

Notes: accepted by many PETSc functions to not set a parameter and instead use some default

This macro does not exist in Fortran; you must use PETSC_NULL_INTEGER, PETSC_NULL_DOUBLE_PRECISION etc

### See Also

PETSC_DECIDE, PETSC_DEFAULT, PETSC_IGNORE, PETSC_DETERMINE

Level:beginner
Location:include/petsc.h
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages

### Examples

src/sys/examples/tutorials/ex2.c.html
src/vec/is/examples/tutorials/ex4.c.html
src/vec/examples/tutorials/ex1.c.html
src/vec/examples/tutorials/ex1e.c.html
src/vec/examples/tutorials/ex3.c.html
src/vec/examples/tutorials/ex5.c.html
src/vec/examples/tutorials/ex6.c.html
src/vec/examples/tutorials/ex9.c.html
src/vec/examples/tutorials/ex10.c.html
src/vec/examples/tutorials/ex11.c.html
src/vec/examples/tutorials/ex12.c.html