What is the underlying implementation principle of slices in Go?

In Go, the underlying implementation of slices is achieved through arrays. A slice consists of three parts: a pointer, length, and capacity.

The pointer points to the first element of the underlying array, the length indicates the number of elements currently included in the slice, and the capacity represents the number of elements in the underlying array that can be accessed from the pointer onwards.

When a slice is created, Go automatically creates an underlying array and points the pointer to the first element of the array, while initializing the length and capacity to the same value. If the number of elements added to the slice exceeds its capacity, Go will automatically create a new underlying array and copy the original elements into the new array. This ensures the continuity of the slice.

When a slice is passed to a function, the function receives a copy of the slice, but this copy shares the underlying array. Therefore, modifying elements in the slice within the function will affect the original slice and the underlying array.

In summary, the underlying principle of slice implementation is to reference and manage the underlying array through pointers, length, and capacity, ensuring the continuity and shared nature of the slice. This design gives slice advantages in both performance and flexibility.