• ← DeleteDuplicates
• → Gather

Flatten

WMA link

Flatten[expr]

flattens out nested lists in expr.

Flatten[expr, n]

stops flattening at level n.

Flatten[expr, n, h]

flattens expressions with head h instead of List.

• • Flatten[{{a, b}, {c, {d}, e}, {f, {g, h}}}]

• • Flatten[{{a, b}, {c, {e}, e}, {f, {g, h}}}, 1]

• • Flatten[f[a, f[b, f[c, d]], e], Infinity, f]

• • Flatten[{{a, b}, {c, d}}, {{2}, {1}}]

• • Flatten[{{a, b}, {c, d}}, {{1, 2}}]

Flatten also works in irregularly shaped arrays

• • Flatten[{{1, 2, 3}, {4}, {6, 7}, {8, 9, 10}}, {{2}, {1}}]