offset from the end of arr. arr[ n m] arr[ n, len] Returns a partial string. arr[ n]= item arr[r m]= array arr[r, len]= array Assigns item or arr to the specified elements. arr = [0, 1, 2, 3, 4, 5] arr[0 2] = ["a", "b"] # arr => ["a", "b", 3, 4, 5] arr[1, 0] = ["
c"] # arr => ["a[r]