
find/filter(func) – filter elements through the function, return first/all values that make it return true.includes(value) – returns true if the array has value, otherwise false.indexOf/lastIndexOf(item, pos) – look for item starting from position pos, return the index or -1 if not found.

If any of items is an array, then its elements are taken.

concat(.items) – returns a new array: copies all members of the current one and adds items to it.slice(start, end) – creates a new array, copies elements from index start till end (not inclusive) into it.items) – at index pos deletes deleteCount elements and inserts items. unshift(.items) – adds items to the beginning.

