# Question about expression dialog

**URL:** <https://forum.openrefine.org/t/question-about-expression-dialog/1409>\
**Category:** Support and Helpdesk\
**Created:** [March 24, 2024, 3:22am UTC](https://forum.openrefine.org/t/question-about-expression-dialog/1409 "2024-03-24T03:22:17Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![zyadtaha](https://dub1.discourse-cdn.com/flex017/user_avatar/forum.openrefine.org/zyadtaha/32/949_2.png) [@zyadtaha](https://forum.openrefine.org/u/zyadtaha)\
**Post date:** [March 24, 2024, 3:22am UTC](https://forum.openrefine.org/t/question-about-expression-dialog/1409/1 "2024-03-24T03:22:17Z")

</div>

What type of errors that when occurred the new column will be set to blank ? As if i made a syntax error it just pops up an alert.  
And how the result of 'store error' option looks like?  
I tried to look after the documentation but i found nothing.  
Thanks in advance.

 ![image](https://europe1.discourse-cdn.com/flex017/uploads/openrefine/original/1X/4c4252cd68cd925d1f11ced08dfaeb13340ac80f.png)

---

<div class="post-metadata">

**Author:** ![antonin\_d](https://dub1.discourse-cdn.com/flex017/user_avatar/forum.openrefine.org/antonin_d/32/32_2.png) [@antonin\_d](https://forum.openrefine.org/u/antonin_d)\
**Post date:** [March 24, 2024, 6:33pm UTC](https://forum.openrefine.org/t/question-about-expression-dialog/1409/2 "2024-03-24T18:33:07Z")

</div>

For instance, you could invoke the `parseJson` function on a string that isn't valid JSON: `parseJson("{")` should give you an error that can be stored.

---

<div class="post-metadata">

**Author:** ![jquartel](https://dub1.discourse-cdn.com/flex017/user_avatar/forum.openrefine.org/jquartel/32/869_2.png) [@jquartel](https://forum.openrefine.org/u/jquartel)\
**Post date:** [March 25, 2024, 7:47am UTC](https://forum.openrefine.org/t/question-about-expression-dialog/1409/3 "2024-03-25T07:47:57Z")

</div>

The 'on error' settings refer to an error in processing of the cell with the expression, not an error in the expression itself. So in the example below, there is an error when attepting to apply the expression to an an empty cell -- you have the option of leaving the new cell blank, storing the error message in the cell, or copying the original cell value into the new cell.

 ![Screenshot 2024-03-25 at 07.43.06](https://europe1.discourse-cdn.com/flex017/uploads/openrefine/original/1X/d069cd54ddc742541ec8ef506541215d3c9fa643.png)

---

<div class="post-metadata">

**Author:** ![thadguidry](https://dub1.discourse-cdn.com/flex017/user_avatar/forum.openrefine.org/thadguidry/32/653_2.png) [@thadguidry](https://forum.openrefine.org/u/thadguidry)\
**Post date:** [March 25, 2024, 8:02am UTC](https://forum.openrefine.org/t/question-about-expression-dialog/1409/4 "2024-03-25T08:02:55Z")

</div>

@jquartel I like your phrasing on this, John. Update our Docs with that!