### 6.4 Comma-Separated Lists ¶

Comma-separated lists 2 are the basic argument type to all Octave functions—both for input and return arguments. In the example

    max (a, b)

‘`a, b`’ is a comma-separated list. Comma-separated lists can appear on both the right and left hand side of an assignment. For example

    x = [1 0 1 0 0 1 1; 0 0 0 0 0 0 7];
    [i, j] = find (x, 2, "last");

Here, ‘`x, 2, "last"`’ is a comma-separated list constituting the input arguments of `find`. `find` returns a comma-separated list of output arguments which is assigned element by element to the comma-separated list ‘`i, j`’.

Another example of where comma-separated lists are used is in the creation of a new array with `[]` (see Matrices) or the creation of a cell array with `{}` (see Basic Usage of Cell Arrays). In the expressions

    a = [1, 2, 3, 4];
    c = {4, 5, 6, 7};

both ‘`1, 2, 3, 4`’ and ‘`4, 5, 6, 7`’ are comma-separated lists.

Comma-separated lists cannot be directly manipulated by the user. However, both structure arrays and cell arrays can be converted into comma-separated lists, and thus used in place of explicitly written comma-separated lists. This feature is useful in many ways, as will be shown in the following subsections.

#### Footnotes

##### (2)

Comma-separated lists are also sometimes referred to as cs-lists.