Changing from 'float64' to 'int' for Values did Unmarshal using 'map[string]interface{}'

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golang

This sample is for changing from “float64” to “int” for values did unmarshal using map[string]interface{}.

When it did unmarshal using map[string]interface{}, a number with “int” was changed to “float64”. And it shows an error as follows.

Error :

panic: interface conversion: interface {} is float64, not int

Sample Script : It solves using following script.

package main

import (
    "encoding/json"
    "fmt"
    "reflect"
)

func main() {
    data := `{"key": 10}`
    var i map[string]interface{}
    json.Unmarshal([]byte(data), &i)

    val1 := i["key"]
    fmt.Printf("%v, %v\n", val1, reflect.TypeOf(val1)) // 10, float64

    i["key"] = int(i["key"].(float64))
    val2 := i["key"]
    fmt.Printf("%v, %v\n", val2, reflect.TypeOf(val2)) // 10, int
}

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