AppendTo

AppendTo[s,elem]

appends elem to the value of s, and resets s to the result.

Details

Examples

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Basic Examples  (2)

Assign l to a list:

Include a new value at the end of the list:

The value assigned to l has changed:

Append to an Association:

Generalizations & Extensions  (3)

Use a head other than List:

This assigns s to a sparse matrix:

Add a row to the matrix:

Appending an element with inconsistent dimensions requires converting to ordinary lists:

Append to a shared list in parallel:

Applications  (1)

Assign m to be a 2×2 matrix:

Append a row to m:

Append a column to m:

m is now a 3×3 matrix:

Possible Issues  (6)

The first argument must be a variable:

The first argument must be a variable with a value:

The first argument must be assigned to something which can be appended to:

Something for which AtomQ is True cannot be appended to:

Using AppendTo on a column of a matrix replaces column values:

Append to a matrix column:

Reset the column values with the new value:

Using AppendTo to accumulate values in large loops can be slow:

There are many alternatives, such as using Reap and Sow:

When working on a shared list in parallel, AppendTo is atomic:

The seemingly equivalent expression using Append is not atomic:

Introduced in 1988
 (1.0)
 |
Updated in 2003
 (5.0)
2014
 (10.0)