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Prepend

Prepend

Prepend[expr,elem]

gives expr with elem prepended.

represents an operator form of Prepend that can be applied to an expression.

Details

Prepend works on SparseArray objects, returning ordinary lists if necessary.
Prepend can be used on Association objects. Single new elements are specified in the form key->value. New values replace older ones if their keys are the same.
Multiple elements to prepend to an association can be specified in the form {key₁->value₁,key₂->value₂, …}.
Prepend[elem][expr] is equivalent to Prepend[expr,elem].

Examples

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Basic Examples (3)

Prepend to an Association:

Prepend several rules to an Association:

Generalizations & Extensions (1)

Use a head other than List:

Applications (4)

Prepend a row to a matrix:

Prepend to each row in a matrix:

Prepend a vector to a matrix:

Successively prepend to a list:

Possible Issues (1)

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