30-seconds-of-code/snippets/array-concatenation.md

Array concatenation

Use Array spread operators (...) to concatenate an array with any additional arrays and/or values, specified in args.

const ArrayConcat = (arr, ...args) => [...arr,...args]; 
// ArrayConcat([1], [1, 2, 3, [4]]) -> [1, 1, 2, 3, [4]]