Golang: simple map operations

Hi there, today we'd like to introduce you a package which will help you to deal some maps in a json path way.

Let's assume you have a response from some service:

var document map[string]interface{}  
err := json.Unmarshal(someCrazyResponse, &document)  

and your document map is

    "one": []map[string]interface{}{
            "two": []map[string]interface{}{
                {"three": "got three"},
                {"four": "got four"},
            "two": []map[string]interface{}{
                {"five": "got five"},
                {"six": "got six"},
            "two": []map[string]interface{}{
                {"seven": "got seven"},
                {"eight": "got eight"},
            "three": []map[string]interface{}{
                {"four": map[string]interface{}{
                    "five": "six",
                {"seven": map[string]interface{}{
                    "eight": "ten",

You need to extract a property located in one[2].two[1].eight which is currently ten

In golang it's a quite long string:

myVar := document["one"].([]map[string]interface{})[2]["two"].([]map[string]interface{})[1]["eight"]  

It also can panic because in some of these documents there is no such property one[3].two

The package

So, we have developed a go-json-map package.

Using it you can:

  • get a property

    myVar, err := GetProperty(document, "one[2].two[1].eight")
  • create some property which does not exist in a document

    err := CreateProperty(document, "path.which.does.not.exist", "some value")
    err := CreateProperty(document, "path/which/does/not/exist/separated/using/slashes/", "some value", "/")
  • update missing or existing property

    err := UpdateProperty(document, "path.which.should.be.updated", "some value")
    err := UpdateProperty(document, "path/which/does/not/exist/separated/using/slashes/", "some value", "/")
    err := UpdateProperty(document, "one[2].two[1].eight",  "eleven")
    err := UpdateProperty(document, "one[3].three[2].four", []int{1,2,3,4})
  • delete a property

    err := DeleteProperty(document, "one[3].three[1].seven.eight")


This package allows you to work with maps a bit easier :D