ReplacePart¶ Replaces element at a specific position. $ wo 'ReplacePart[{a, b, c}, 2 -> x]' {a, x, c} $ wo 'ReplacePart[{1, 2, 3, 4}, 1 -> 0]' {0, 2, 3, 4} $ wo 'ReplacePart[{a, b, c}, -1 -> z]' {a, b, z}