Best way to swap variable values in Go?
There is a function called Swapper which takes a slice and returns a swap function. This swap function takes 2 indexes and swap the index values in the slice.
package main
import (
"fmt"
"reflect"
)
func main() {
s := []int{1, 2, 3}
fmt.Printf("Before swap: %v\n", s)
swapF := reflect.Swapper(s)
swapF(0, 1)
fmt.Printf("After swap: %v\n", s)
}
Try it
Output
Before swap: [1 2 3]
After swap: [2 1 3]
Yes, you can swap values like python.
a, b := 0, 1
fmt.Printf("Before swap a = %v, b = %v\n", a, b)
b, a = a, b
fmt.Printf("After swap a = %v, b = %v\n", a, b)
Output
Before swap a = 0, b = 1
After swap a = 1, b = 0
Yes, it is possible. Assuming a
and b
have the same type, the example provided will work just fine. For example:
a, b := "second", "first"
fmt.Println(a, b) // Prints "second first"
b, a = a, b
fmt.Println(a, b) // Prints "first second"
Run sample on the playground
This is both legal and idiomatic, so there's no need to use an intermediary buffer.
Yes you can swap by using
a, b = b, a
So if a = 1 and b= 2, then after executing
a , b = b, a
you get a = 2 and b = 1
Also, if you write
a, b, a = b, a, b
then it results b = 1 and a = 2
Yes it is possible to swap elements using multi-value assignments:
i := []int{1, 2, 3, 4}
fmt.Println(i)
i[0], i[1] = i[1], i[0]
fmt.Println(i)
a, b := 1, 2
fmt.Println(a, b)
a, b = b, a // note the lack of ':' since no new variables are being created
fmt.Println(a, b)
Output:
[1 2 3 4]
[2 1 3 4]
1 2
2 1
Example: https://play.golang.org/p/sopFxCqwM1
More details here: https://golang.org/ref/spec#Assignments