Skip to content

Lists

Lists (also called arrays or sequences in some languages) are ordered collections of values. They are useful when you need an indexed, iterable container that can grow or shrink.

# Creation
lst = [1, 2, 3]
empty = []

# Indexing and slicing
first = lst[0]
tail = lst[1:]

# Mutating
lst.append(4)
lst[1] = 20

# Comprehensions
squares = [x*x for x in range(5)]

# Iteration
for i, v in enumerate(lst):
    print(i, v)

% Row vector as a list
lst = [1 2 3];
empty = [];

% Indexing (1-based)
first = lst(1);
tail = lst(2:end);

% Grow by concatenation
lst = [lst 4];

% Iterate
for i = 1:numel(lst)
  disp([i lst(i)])
end

Gotchas

  • Lists are mutable in Python; assigning one list to another name creates a shared reference.
  • Slicing in Python creates a shallow copy; modifying the slice doesn't change the original list.
  • Matlab vectors are 1-based and are arrays by default; use cell arrays {} for heterogeneous collections.
  • Avoid using mutable objects as default function arguments in Python.