InitializationValue

InitializationValue[sym]

represents the settable persistent value with which the symbol sym will be initialized.

InitializationValue["context`name"]

represents the settable initialization value for the symbol with the specified complete name.

InitializationValue[sym,{loc1,}]

specifies the persistence locations to search for a possible initialization value.

Details and Options

Examples

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Basic Examples  (2)

Set a value to be evaluated every time the kernel starts:

Set an initialization value for a variable:

Initialize the variable from the persistent value in the current kernel session:

Generalizations & Extensions  (1)

Set an initialization value for parallel subkernels:

All newly launched parallel subkernels use the given value:

Remove the initialization value:

Options  (5)

EvaluationEnvironment  (1)

Set an initialization value for parallel subkernels:

MergingFunction  (1)

Establish a default value and merging function for an initialization value:

Add an initialization value at the front end persistence location:

The resulting initialization value now uses the default merging function:

When the variable is initialized, the default merging function is used:

ValuePreprocessingFunction  (1)

Define a value preprocessing function for a particular initialization value that accepts only integers:

Assign an integer at any persistence location:

Assigning anything else generates an error, and the assignment is not performed:

PersistenceTime  (1)

Define an initialization that will expire in 5 seconds:

ExpirationDate  (1)

Define an initialization value that expires at the beginning of next year:

Applications  (2)

Override the default persistence base in all kernels started under the current front end session:

Quit and restart the kernel:

Set a value for $GeoLocation tied to your login account:

Properties & Relations  (2)

Initialization values are stored in persistent objects:

List the existing initialization values in all editable persistence locations:

Remove them:

Possible Issues  (1)

Create two initialization values for a symbol in different locations:

Remove by default removes only the value in the location given by $PersistenceBase:

Remove all values that might exist anywhere in the locations given by $PersistencePath:

Introduced in 2017
 (11.2)
 |
Updated in 2019
 (12.0)