:orphan:
# PetscBool
Logical variable. Actually an enum in C and a logical in Fortran.
## Synopsis
```
typedef enum {
PETSC_FALSE,
PETSC_TRUE
} PetscBool;
```
## Developer Note
Why have `PetscBool`, why not use bool in C? The problem is that K and R C, C99 and C++ all have different mechanisms for
boolean values. It is not easy to have a simple macro that that will work properly in all circumstances with all three mechanisms.
## See Also
`PETSC_TRUE`, `PETSC_FALSE`, `PetscNot()`, `PetscBool3`
## Level
beginner
## Location
include/petscsystypes.h
## Examples
src/dm/dt/dualspace/impls/lagrange/tutorials/ex1.c
src/dm/impls/stag/tutorials/ex2.c
src/dm/impls/stag/tutorials/ex3.c
src/dm/impls/stag/tutorials/ex4.c
src/dm/impls/stag/tutorials/ex6.c
src/dm/label/tutorials/ex1.c
src/ksp/ksp/tutorials/ex42.c
src/ksp/ksp/tutorials/ex43.c
src/ksp/ksp/tutorials/ex72.c
src/ts/utils/dmplexlandau/tutorials/ex2.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/include/petscsystypes.h)
[Index of all Sys routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)