What is the underlying principle of slices in golang?

Slices in Golang are a flexible and dynamic data structure that can be seen as a wrapper for arrays. The underlying principles of slices mainly include the following aspects:

1. Data structure: The underlying data structure of a slice includes a pointer to the underlying array, the length of the slice, and the capacity of the slice. The pointer points to the starting position of the underlying array, the length indicates the number of elements currently included in the slice, and the capacity represents the length of the underlying array.
2. Dynamic expansion: when the number of elements in a slice exceeds its capacity, the underlying structure automatically expands. During expansion, a new, larger underlying array is created and the original elements are copied into the new array. The slice’s pointer, length, and capacity are updated simultaneously.
3. Multiple slices can share the same underlying array: when one slice changes the elements of the underlying array, other slices that share the same underlying array will also be affected. This design can reduce memory overhead, but it is important to be cautious as operations on shared slices may result in unexpected side effects.
4. Zero value of a slice: The zero value of a slice is nil, indicating an uninitialized slice. The pointer, length, and capacity of a zero value slice are all 0. To initialize a zero value slice, the make function must be used to allocate an underlying array and return a usable slice.

In summary, the underlying principle of slicing is to manage the underlying array through pointers, length, and capacity, and provides convenient methods for dynamic resizing and sharing of the underlying array. This design makes slices more efficient and flexible when handling dynamic data collections.