why json.Unmarshal method convert number value (in json string) to float value (in golang)?

[mthhk]

BIAGT

[mvdan]

Please read the documentation carefully: https://golang.org/pkg/encoding/json/#Unmarshal

To unmarshal JSON into an interface value, Unmarshal stores one of these in the interface value:
[...]
float64, for JSON numbers

[mthhk]

of cause i read it。
i mean，if go stories number value to float，the precision will be lost；
for an example ，how to Unmarshal {"key":123123123123123123123123"} ???

m := make(map[string]interface{})
originJson := {"key":1123123123123123123}
json.Unmarshal([]byte(originJson), &m)
fmt.Printf("origin json %s -> after parsed %v", originJson, m["key"])
===output====
origin json {"key":1123123123123123123} -> after parsed 1.1231231231231231e+181123123123123123123,--- PASS: TestInvocation412131 (0.00s)

[dominikh]

Unlike many projects on GitHub, the Go project does not use its bug tracker for general discussion or asking questions. We only use our bug tracker for tracking bugs and tracking proposals going through the Proposal Process.

Please see https://golang.org/wiki/Questions for good places to ask questions.