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KeyUnion

Status: Stable

documented, exercised by the test suite and/or worked examples, with no known limitations recorded.

Description

KeyUnion[{assoc1, assoc2, ...}]
    Gives the list of associations padded to the union of all their keys;
    a key absent from an association is filled with Missing["KeyAbsent", key].

Examples

All examples below are verified against the current Mathilda build.

In[1]:= KeyUnion[{<|"a" -> 1, "b" -> 2|>, <|"b" -> 3, "c" -> 4|>}]
Out[1]= {<|"a" -> 1, "b" -> 2, "c" -> Missing["KeyAbsent", "c"]|>, <|"a" -> Missing["KeyAbsent", "a"], "b" -> 3, "c" -> 4|>}

Implementation notes

Attributes: Protected.

Implementation status

Stable — documented, exercised by the test suite and/or worked examples, with no known limitations recorded.

References