Go，Golang：遍历struct

Question

http://play.golang.org/p/fJACxhSrXX

I want to traverse through an array of structs.

 func GetTotalWeight(data_arr []struct) int {
    total := 0
    for _, elem := range data_arr {
        total += elem.weight
    }
    return total
 }

But I am getting syntax error

   syntax error: unexpected ), expecting {

Is it possible to traverse through structs?

Answer 1

Your function is almost entirely correct. You want to define TrainData as a type, and change the type signature of GetTotalWeight to []TrainData, not []struct, like so:

import "fmt"

type TrainData struct {
    sentence string
    sentiment string
    weight int
}

var TrainDataCity = []TrainData {
    {"I love the weather here.", "pos", 1700},
    {"This is an amazing place!", "pos", 2000},
    {"I feel very good about its food and atmosphere.", "pos", 2000},
    {"The location is very accessible.", "pos", 1500},
    {"One of the best cities I've ever been.", "pos", 2000},
    {"Definitely want to visit again.", "pos", 2000},
    {"I do not like this area.", "neg", 500},
    {"I am tired of this city.", "neg", 700},
    {"I can't deal with this town anymore.", "neg", 300},
    {"The weather is terrible.", "neg", 300},
    {"I hate this city.", "neg", 100},
    {"I won't come back!", "neg", 200},
}

func GetTotalWeight(data_arr []TrainData) int {
    total := 0
    for _, elem := range data_arr {
        total += elem.weight
    }
    return total
}

func main() {
    fmt.Println("Hello, playground")
    fmt.Println(GetTotalWeight(TrainDataCity))
}

Running this gives:

Hello, playground
13300