Can you insert more elements into an existing array than its current length?

In Go, arrays have a fixed length specified at declaration, and it cannot be changed. If you need to add more elements than the current array length, it is impossible.

For dynamic addition of elements, slices are used, which can be expanded with the append function.

Example:

var arr [3]int = [3]int{1, 2, 3} // array of fixed length 3
// arr = append(arr, 4) // error, append does not work with arrays

slice := []int{1, 2, 3} // slice
slice = append(slice, 4, 5) // now the slice contains 5 elements

Thus, to insert more elements than the current length, you need to use slices, not arrays.