一次添加两个项目以构造for循环

Question

I'm trying to add 2 items at once to a struct array, then continuously every 2 items create a new struct array and append to the final Container struct. I'm struggling to find the proper way of doing this.

To further illustrate what I mean:

package main

import "fmt"

type Container struct {
    Collection []SubContainer
}

type SubContainer struct {
    Key   string
    Value int
}

func main() {
    commits := map[string]int{
        "a": 1,
        "b": 2,
        "c": 3,
        "d": 4,
        "e": 5,
        "f": 6,
    }

    sc := []SubContainer{}
    c := Container{}

    for k, v := range commits {
        sc = append(sc, SubContainer{Key: k, Value: v})
    }

    for _, s := range sc {
        c.Collection = append(c.Collection, s)
    }

    fmt.Println(c)
}

Link: https://play.golang.org/p/OhSntFT7Hp

My desired behaviour is to loop through all the commits, and every time the SubContainer reaches len(2), append to the Container, and create a new SubContainer until the for loop is complete. If there's an uneven number of elements, then the last SubContainer would just hold one element and append to Container like normal.

Does anyone have any suggestions on how to do this? Apologies if this is a obvious answer, very new to Go!

Answer 1

You can "reset" a slice by setting it to nil. Also, you may not be aware that nil-slices work just fine with append:

var sc []SubContainer
c := Container{}

for k, v := range commits {
    sc = append(sc, SubContainer{Key: k, Value: v})
    if len(sc) == 2 {
        c.Collection = append(c.Collection, sc...)
        sc = nil
    }
}
if len(sc) > 0 {
    c.Collection = append(c.Collection, sc...)

}

https://play.golang.org/p/ecj52fkwpO