is an attribute that prevents any values associated with a symbol from being modified.


Protected
is an attribute that prevents any values associated with a symbol from being modified.
Details

- Many built‐in Wolfram Language functions have the attribute Protected.
- SetOptions can be used on symbols with attribute Protected that do not also have the Locked attribute.
Examples
open all close allScope (1)
Properties & Relations (5)
Protecting a symbol is equivalent to setting the Protected attribute:
Unprotecting a symbol is equivalent to clearing the Protected attribute:
No more definitions can be made for a protected symbol:

Neither can definitions be cleared:

To modify definitions of a protected symbol, unprotect it first:

SetOptions can be used the change the default options of a protected function:
Change the options of D:
A symbol that is locked and protected can no longer be changed:



Tech Notes
Related Guides
History
Introduced in 1988 (1.0)
Text
Wolfram Research (1988), Protected, Wolfram Language function, https://reference.wolfram.com/language/ref/Protected.html.
CMS
Wolfram Language. 1988. "Protected." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Protected.html.
APA
Wolfram Language. (1988). Protected. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Protected.html
BibTeX
@misc{reference.wolfram_2025_protected, author="Wolfram Research", title="{Protected}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/Protected.html}", note=[Accessed: 14-August-2025]}
BibLaTeX
@online{reference.wolfram_2025_protected, organization={Wolfram Research}, title={Protected}, year={1988}, url={https://reference.wolfram.com/language/ref/Protected.html}, note=[Accessed: 14-August-2025]}