2 ways to delete an element from a slice

yourbasic.org/golang

Fast version (changes order)

a := []string{"A", "B", "C", "D", "E"} i := 2 // Remove the element at index i from a. a[i] = a[len(a)-1] // Copy last element to index i. a[len(a)-1] = "" // Erase last element (write zero value). a = a[:len(a)-1] // Truncate slice. fmt.Println(a) // [A B E D]

The code copies a single element and runs in constant time.

Slow version (maintains order)

a := []string{"A", "B", "C", "D", "E"} i := 2 // Remove the element at index i from a. copy(a[i:], a[i+1:]) // Shift a[i+1:] left one index. a[len(a)-1] = "" // Erase last element (write zero value). a = a[:len(a)-1] // Truncate slice. fmt.Println(a) // [A B D E]

The code copies len(a) - i - 1 elements and runs in linear time.

转载于:https://www.cnblogs.com/oxspirt/p/11273308.html