Append

Append[expr, elem] gives expr with elem appended.

Append[elem] represents an operator form of Append that can be applied to an expression.

Examples

Append an element to a list:

Append[{a, b, c}, d]
(* {a, b, c, d} *)

Using the operator form:

Append[x][{1, 2, 3}]
(* {1, 2, 3, x} *)

Please visit the official Wolfram Language Reference for more details.