【已解决】请问golang怎么反序列化二维数组的json

a := [3][4]string{
    {"0", "1", "2", "3"},
    {"4", "5", "6", "7"},
    {"8", "9", "10", "11"}}
bytes, _ := json.Marshal(a)
jsonStr := string(bytes)
fmt.Println(jsonStr) // 打印 [["0","1","2","3"],["4","5","6","7"],["8","9","10","11"]]
var b [][]string
c := json.Unmarshal([]byte(jsonStr), &b)
fmt.Println(c) // 打印 <nil>

请问怎样把jsonStr反序列化回来？

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【已解决】
我以为答案保存在了c，原来保存在b，犯了低级错误，折腾我半天