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.



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