# PetscOptionsEList
Puts a list of option values that a single one may be selected from Logically Collective on the communicator passed in `PetscOptionsBegin()`


## Synopsis
```
#include "petscsys.h"
PetscErrorCode  PetscOptionsEList(const char opt[],const char ltext[],const char man[],const char *const *list,PetscInt ntext,const char currentvalue[],PetscInt *value,PetscBool  *set)
```

## Input Parameters

- ***opt -*** option name
- ***ltext -*** short string that describes the option
- ***man -*** manual page with additional information on option
- ***list -*** the possible choices (one of these must be selected, anything else is invalid)
- ***ntext -*** number of choices
- ***currentvalue -*** the current value; caller is responsible for setting this value correctly. Normally this is done with


```none
PetscOptionsElist(..., obj->value,&value,&flg);
```
```none
if (flg) {
```


## Output Parameters

- ***value -*** the index of the value to return
- ***set -*** `PETSC_TRUE` if found, else `PETSC_FALSE`





## Notes
Must be between a `PetscOptionsBegin()` and a `PetscOptionsEnd()`

If the user does not supply the option at all value is NOT changed. Thus
you should ALWAYS initialize value if you access it without first checking if the set flag is true.

See `PetscOptionsFList()` for when the choices are given in a `PetscFunctionList()`


## See Also
 `PetscOptionsGetInt()`, `PetscOptionsGetReal()`,
`PetscOptionsHasName()`, `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`,
`PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
`PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
`PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
`PetscOptionsFList()`, `PetscOptionsEnum()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/objects/aoptions.c.html#PetscOptionsEList">src/sys/objects/aoptions.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex29.c.html">src/ksp/ksp/tutorials/ex29.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex32.c.html">src/ksp/ksp/tutorials/ex32.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex35.cxx.html">src/ksp/ksp/tutorials/ex35.cxx.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex36.cxx.html">src/ksp/ksp/tutorials/ex36.cxx.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex71.c.html">src/ksp/ksp/tutorials/ex71.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex73.c.html">src/ksp/ksp/tutorials/ex73.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex12.c.html">src/snes/tutorials/ex12.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex17.c.html">src/snes/tutorials/ex17.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex36.c.html">src/snes/tutorials/ex36.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex62.c.html">src/snes/tutorials/ex62.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex63.c.html">src/snes/tutorials/ex63.c.html</A><BR>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/objects/aoptions.c)


[Index of all Sys routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
