Unevaluated

Unevaluated[expr]

represents the unevaluated form of expr when it appears as the argument to a function.

Details

  • f[Unevaluated[expr]] effectively works by temporarily setting attributes so that f holds its argument unevaluated, then evaluating f[expr].

Examples

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Basic Examples  (1)

Feed an unevaluated expression to Length:

Applications  (1)

Use HoldAll and Unevaluated to suppress evaluation of symbols wherever they would occur:

Find the length of a symbol's name even if it has a value:

Properties & Relations  (3)

Unevaluated works only where it appears; it is not propagated:

Unevaluated stops Evaluate:

Unevaluated inside a held function remains:

Introduced in 1991
 (2.0)