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HM
HM

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Replace json values using a mapping json

#go #codenewbie #beginners #tutorial

Problem statement

Given an input JSON like this 

{ "results": [ { "id": 1, "relationx_id": "11" }, { "id": 2, "relationx_id": "22" } ], "lookup_key": "relationx_id" }
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and a mapping JSON like this 

{ "11": "88", "22": "99" }
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Use the lookup_key to replace the value of the key as per the mapping JSON. The result should look like this 

{ "lookup_key": "relationx_id", "results": [ { "id": 1, "relationx_id": "88" }, { "id": 2, "relationx_id": "99" } ] }
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Solution 

package main import ( "encoding/json" "fmt" ) var inp string = `{ "results": [ { "id": 1, "relationx_id": "11" }, { "id": 2, "relationx_id": "22" } ], "lookup_key": "relationx_id" }` var mapping string = `{ "11": "88", "22": "99" }` func main() { var inpJ map[string]interface{} json.Unmarshal([]byte(inp), &inpJ) // fmt.Printf("%+v\n", inpJ) var mappingJ map[string]string json.Unmarshal([]byte(mapping), &mappingJ) // fmt.Printf("%+v\n", mappingJ) lookupKey := inpJ["lookup_key"].(string) // fmt.Printf("%+v\n", lookupKey) for _, result := range inpJ["results"].([]interface{}) { resultMap := result.(map[string]interface{}) for k, v := range resultMap { if k == lookupKey { resultMap[k] = mappingJ[v.(string)] } } } // fmt.Printf("%+v\n", inpJ) b, _ := json.MarshalIndent(inpJ, "", " ") fmt.Println(string(b)) }
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