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AppendTo

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

MORE INFORMATION

AppendTo is equivalent to s=Append[s, elem].

AppendTo does not evaluate s.

You can use AppendTo repeatedly to build up a list, though Sow and Reap will usually be more efficient. »

AppendTo works on SparseArray objects, returning ordinary lists if necessary. »

EXAMPLES

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Basic Examples (1)

Assign

to a list:

Include a new value at the end of the list:

The value assigned to

has changed:

Assign

to a list:

In[1]:=

Out[1]=

Include a new value at the end of the list:

In[2]:=

Out[2]=

The value assigned to

has changed:

In[3]:=

Out[3]=

Generalizations & Extensions (2)

Use a head other than List:

This assigns

to a sparse matrix:

Add a row to the matrix:

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

Applications (1)

Assign

to be a 2×2 matrix:

Append a row to

Append a column to

is now a 3×3 matrix:

Possible Issues (4)

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 to accumulate values in large loops can be slow:

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