This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
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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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