DOCUMENTATION CENTER SEARCH
Mathematica
>
Evaluation Control
>
Built-in
Mathematica
Symbol
Evaluation
Non-Standard Evaluation
Tutorials »
|
HoldPattern
HoldForm
HoldComplete
Unevaluated
HoldAll
HoldAllComplete
HoldFirst
HoldRest
Symbol
Defer
See Also »
|
Evaluation Control
Expressions
More About »
Hold
Hold
[
expr
]
maintains
expr
in an unevaluated form.
MORE INFORMATION
Hold
has attribute
HoldAll
, and performs no operation on its arguments.
Hold
is removed by
ReleaseHold
.
»
Hold
[
e
1
,
e
2
,
...
]
maintains a sequence of unevaluated expressions to which a function can be applied using
Apply
.
Even though
expr
itself is not evaluated,
Hold
[
expr
]
may still evaluate if
expr
is of the form
f
[
args
]
, and upvalues for
f
have been defined.
»
EXAMPLES
CLOSE ALL
Basic Examples
(1)
Hold an expression to prevent evaluation:
In[1]:=
Out[1]=
Release the hold:
In[2]:=
Out[2]=
Applications
(2)
Properties & Relations
(9)
SEE ALSO
HoldPattern
HoldForm
HoldComplete
Unevaluated
HoldAll
HoldAllComplete
HoldFirst
HoldRest
Symbol
Defer
TUTORIALS
Evaluation
Non-Standard Evaluation
MORE ABOUT
Evaluation Control
Expressions
New in 1
© 2008 Wolfram Research, Inc.