Assigning a slice of struct

Question

I am trying to represent a slice data as json format so that I can use this vs-code-extension .

But I am getting error in the last line of the for loop.

Error: append(formatted.Rows, col_i) (value of type []RowStructure) is not usedcompilerUnusedExpr

Please help me find out what am I doing wrong and what should be the correct way of assigning slice of structs.

Thankyou

type ColumnStructure struct{
    Content string
    Tag string
}
type RowStructure struct{
    Column ColumnStructure
}

type format struct{
    Kind map[string]bool
    Text string
    Rows []RowStructure
}

func serialize(s []int){
    var formatted format
    for i := 0; i < len(s); i++ {
        var col_i = ColumnStructure{
            Content: string(s[i]),
            Tag: string(s[i]),
        }
        append(formatted.Rows,col_i)
    }
}

func main() {
    var s = []int{1, 12, 30, 4, 5}
    formatted_data := serialize(s)
    fmt.Println(formatted_data)
    }

Answer 1

After doing certain changes to the code, following code works fine now. But I am still not able to get the visualizations from this vs-code-extension.

type ColumnStructure struct {
    Content string
    Tag     string
}
type RowStructure struct {
    Column ColumnStructure
}

type format struct {
    Kind map[string]bool
    Text string
    Rows []RowStructure
}

func serialize(s []int) format {
    var formatted format
    for i := 0; i < len(s); i++ {
        var col_i = ColumnStructure{
            Content: string(s[i]),
            Tag:     string(s[i]),
        }
        var row = RowStructure{
            Column: col_i,
        }
        formatted.Rows = append(formatted.Rows, row)
    }
    return formatted
}

func main() {
    var s = []int{1, 12, 30, 4, 5}
    formatted_data := serialize(s)
    fmt.Println(formatted_data)
    for i := 0; i < len(s)-1; i++ {
        if s[i] < s[i+1] {
            s[i], s[i+1] = s[i+1], s[i]
        }
    }
    fmt.Println(s)
}