Summary - Array and slice
- Go course
- Beginner
- Lesson 46/90
- 4 min
Combine slice and append to write a task list.
Arrays and slices summary
Array: fixed length, a value type (copied on assignment), [3]int. Slice: flexible, a view onto an array (shared on assignment), []int; make, append, copy, s[a:b], len, cap. Rule: always assign append's result; when you need an independent copy, use copy or slices.Clone.
import "slices"
s := []int{3, 1, 2}
slices.Sort(s) // [1 2 3]
fmt.Println(slices.Contains(s, 2)) // true
fmt.Println(slices.Index(s, 3)) // 2Two-dimensional slices
A table is built from a slice of slices; each row is created separately:
tablo := make([][]int, 3)
for i := range tablo {
tablo[i] = make([]int, 3)
}
tablo[1][2] = 7
fmt.Println(tablo) // [[0 0 0] [0 0 7] [0 0 0]]Rows can have different lengths (a jagged table).
Practice Unique and sorted
Sort the slice []int{4, 2, 4, 1, 2, 9} with slices.Sort, then remove consecutive duplicates with slices.Compact and print the result.
Starter code
package main
import (
"fmt"
"slices"
)
func main() {
// buraya yaz
}Sample solution
package main
import (
"fmt"
"slices"
)
func main() {
s := []int{4, 2, 4, 1, 2, 9}
slices.Sort(s)
s = slices.Compact(s)
fmt.Println(s)
}Expected output
[1 2 4 9]
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What is the right way to delete the element at index 2 of a slice?
- s.Remove(2)
- s = slices.Delete(s, 2, 3) Correct answer
- delete(s, 2)
- s[2] = nil
Explanation: slices.Delete(s, i, j) removes the range [i, j) and returns the new slice; delete is only for maps.
2 Sort
s := []int{5, 2, 8}
slices.____(s)
fmt.Println(s) // [2 5 8]s := []int{5, 2, 8}
slices.Sort(s)
fmt.Println(s) // [2 5 8]Explanation: slices.Sort sorts the slice in place in ascending order.
3 Group summary
| Term | Meaning |
|---|---|
[3]int |
Array, fixed length |
[]int |
Slice, flexible |
append |
Append and assign |
slices.Clone |
Independent copy |