gives True if a value has been defined for expr, and gives False otherwise.
- ValueQ has attribute HoldAll.
- ValueQ gives False only if expr would not change if it were to be entered as Wolfram Language input.
Examplesopen allclose all
Basic Examples (2)
Only the one argument form of has values associated with it:
Values of symbols:
Conditional definitions; the result depends on the argument:
Properties & Relations (2)
Possible Issues (1)
ValueQ returns True if any evaluation takes place, even though does not match here: