How can elements be added to an existing slice without recreating it?

In Go, to add elements to an existing slice without recreating it, the built-in append function is used. It adds new elements to the slice, increasing its capacity if necessary. If the current capacity allows, it does not create a new underlying array, but simply extends the existing one.

Example:

slice := []int{1, 2, 3}
slice = append(slice, 4, 5) // add elements 4 and 5
fmt.Println(slice) // [1 2 3 4 5]

If the capacity is insufficient, append creates a new array and returns a new slice, so it’s important to assign the result back to the slice variable.