$MessagePrePrint
is a global variable whose value, if set, is applied to expressions before they are included in the text of messages.
Details
![](Files/$MessagePrePrint.en/details_1.png)
- The default value of $MessagePrePrint is Automatic.
- $MessagePrePrint is applied after each expression is wrapped with HoldForm.
Examples
open allclose allBasic Examples (1)
Have expressions in messages print out in TraditionalForm:
![](Files/$MessagePrePrint.en/1.gif)
Restore the default. Now the expressions are shown in StandardForm:
![](Files/$MessagePrePrint.en/2.gif)
Scope (2)
Locally define $MessagePrePrint so that expressions sent to messages are shown in a circle:
![](Files/$MessagePrePrint.en/3.gif)
The local definition does not affect messages outside the Block:
![](Files/$MessagePrePrint.en/4.gif)
Make a list of all expressions sent to messages during a computation:
![](Files/$MessagePrePrint.en/5.gif)
![](Files/$MessagePrePrint.en/6.gif)
Text
Wolfram Research (1991), $MessagePrePrint, Wolfram Language function, https://reference.wolfram.com/language/ref/$MessagePrePrint.html.
CMS
Wolfram Language. 1991. "$MessagePrePrint." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/$MessagePrePrint.html.
APA
Wolfram Language. (1991). $MessagePrePrint. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/$MessagePrePrint.html