Array<T>.prototype.*
concat(: (T | Array<T>)[]): T[]
concat(items)
🔒- Returns a new array that is the concatenation of
this
and allitems
. Non-array parameters are treated as if they were arrays with single elements. - ES3
['a'].concat('b', ['c', 'd']) → [ 'a', 'b', 'c', 'd' ]
- Returns a new array that is the concatenation of
copyWithin(:number, :number, ?:number): this