This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)


represents the unevaluated form of expr when it appears as the argument to a function.
  • effectively works by temporarily setting attributes so that f holds its argument unevaluated, then evaluating .
Feed an unevaluated expression to Length:
Feed an unevaluated expression to Length:
Click for copyable input
Use HoldAll and Unevaluated to suppress evaluation of symbols wherever it would occur:
Find the length of a symbol's name even if it has a value:
Unevaluated works only where it appears; it is not propagated:
Unevaluated inside a held function remains:
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