containers.Map

containers.Map is a string-keyed associative array — a lookup table that maps string keys to values of any type. It is the ccalc equivalent of Python’s dict or JavaScript’s Map.

Creating a map

% Empty map
m = containers.Map();

% From two cell arrays — keys cell + values cell (must be equal length)
prices = containers.Map({'apple', 'banana', 'cherry'}, {1.5, 0.75, 2.0});

All keys must be strings (char arrays or string objects).
Values can be any type: scalar, matrix, string, cell, struct, etc.

Reading values

Use parenthesis indexing with a string key:

prices('apple')     % → 1.5
prices('banana')    % → 0.75

Accessing an absent key is an error:

prices('mango')     % error: Map key 'mango' not found

Writing values

prices('date') = 3.5;      % insert new key
prices('banana') = 0.99;   % update existing key

Count property

prices.Count    % → number of entries (read-only)

Built-in functions

Function	Description
`isKey(m, 'key')`	`1` if key is present, `0` otherwise
`keys(m)`	Cell array of all keys, sorted alphabetically
`values(m)`	Cell array of values in the same sorted-key order
`remove(m, 'key')`	Remove a key in-place (no assignment needed)

m = containers.Map({'c', 'a', 'b'}, {3, 1, 2});

isKey(m, 'a')   % → 1
isKey(m, 'z')   % → 0

k = keys(m)     % → {'a', 'b', 'c'}   (sorted)
v = values(m)   % → {1, 2, 3}         (matching key order)

remove(m, 'b');
m.Count         % → 2

Iterating over a map

m = containers.Map({'x', 'y', 'z'}, {10, 20, 30});
k = keys(m);
for i = 1:m.Count
  fprintf('%s = %g\n', k{i}, m(k{i}));
end

Display

m =

  Map with 3 entries:

    'apple'  → 1.5
    'banana' → 0.75
    'cherry' → 2

Notes

String keys only. Numeric-key maps are not supported.
Value semantics. Assigning m2 = m creates a copy (unlike MATLAB handle semantics). Mutations to m2 do not affect m.
Maps are not persisted by ws/save — same policy as matrices and cells.
remove(m, k) mutates m in-place without an assignment statement, matching MATLAB handle-class behaviour as closely as possible under value semantics.

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