Go package for dealing with maps, slices, JSON and other data.



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Objx - Go package for dealing with maps, slices, JSON and other data.

Get started:


Objx provides the objx.Map type, which is a map[string]interface{} that exposes a powerful Get method (among others) that allows you to easily and quickly get access to data within the map, without having to worry too much about type assertions, missing data, default values etc.


Objx uses a preditable pattern to make access data from within map[string]interface{} easy. Call one of the objx. functions to create your objx.Map to get going:

m, err := objx.FromJSON(json)

NOTE: Any methods or functions with the Must prefix will panic if something goes wrong, the rest will be optimistic and try to figure things out without panicking.

Use Get to access the value you're interested in. You can use dot and array notation too:


Once you have sought the Value you're interested in, you can use the Is* methods to determine its type.

 if m.Get("code").IsStr() { // Your code... }

Or you can just assume the type, and use one of the strong type methods to extract the real value:


If there's no value there (or if it's the wrong type) then a default value will be returned, or you can be explicit about the default value.


If you're dealing with a slice of data as a value, Objx provides many useful methods for iterating, manipulating and selecting that data. You can find out more by exploring the index below.

Reading data

A simple example of how to use Objx:

// Use MustFromJSON to make an objx.Map from some JSON
m := objx.MustFromJSON(`{"name": "Mat", "age": 30}`)

// Get the details
name := m.Get("name").Str()
age := m.Get("age").Int()

// Get their nickname (or use their name if they don't have one)
nickname := m.Get("nickname").Str(name)


Since objx.Map is a map[string]interface{} you can treat it as such. For example, to range the data, do what you would expect:

m := objx.MustFromJSON(json)
for key, value := range m {
  // Your code...


To install Objx, use go get:

go get github.com/stretchr/objx

Staying up to date

To update Objx to the latest version, run:

go get -u github.com/stretchr/objx

Supported go versions

We support the lastest three major Go versions, which are 1.10, 1.11 and 1.12 at the moment.


Please feel free to submit issues, fork the repository and send pull requests!

  • Unable to select map key with dot

    Unable to select map key with dot

    If I have a map where the keys may be domain names and the values are some object, how do I select a field on the value for key "google.com" via Get?

    enhancement help wanted 
    opened by cretz 8
  • Tag v0.1 as v0.1.0

    Tag v0.1 as v0.1.0

    vgo requires that versions have three parts, like v0.1.0, but the only version tagged for objx is v0.1, and so vgo is unable to use that version. Could you please add a tag at the same commit as v0.1, and name it v0.1.0?

    You can do this by:

    git tag -a v0.1.0 v0.1
    git push origin v0.1.0

    This is required to close stretchr/testify#607.

    opened by leighmcculloch 8
  • URLQuery with index slice keys

    URLQuery with index slice keys

    Certain APIs (I believe those written in PHP) seem to be unable to parse correctly URLQuery() result containing slices generated by URLValuesSliceKeySuffix="" or URLValuesSliceKeySuffix="[]".

    The solution is to pass the slices with an index so that they are read correctly.

    For instance, in order to parse slices of the form correctly: objx.Map{"mapSlice": []objx.Map{objx.Map{"age": 40, "sex": "male"}, objx.Map{"height": 152}}} the query needs to be: mapSlice[0][age]=40&mapSlice[0][sex]=male&mapSlice[1][height]=152

    Currently these two forms are possible which don't work: mapSlice[age]=40&mapSlice[sex]=male&mapSlice[height]=152 mapSlice[][age]=40&mapSlice[][sex]=male&mapSlice[][height]=152

    I've modified the code to check for URLValuesSliceKeySuffix="[i]" and use slice indexes when present

    4. to release 
    opened by geseq 7
  • Panic on MustInt()

    Panic on MustInt()


    I have the following JSON structure:


    Objx panics on json.Get("d[0].id").Int(). Test:

        json, err := objx.FromJSON(`{"d":[{"author":{"displayName":"DemoUser3","id":2},"classes":null,"id":9879,"v":{"code":"","created":"2013-09-19T09:38:50+02:00","published":"0001-01-01T00:00:00Z","updated":"2013-09-19T09:38:50+02:00"}}],"s":200}`)
        if !assert.NoError(t, err, "Can't decode output") {
        assert.Equal(t, json.Get("d[0].id").Int(), 9879, "...") 
    opened by an2deg 7
  • Set operator with not expected behavior

    Set operator with not expected behavior

    create map by FromJSON or New(with map[string]interface{}), and Set with fields got the difference result.

    m := objx.FromJSON(`{"a": {"b": 1}}`)
    m.Set("a.c", 2)
    fmt.Println(m.JSON())  // output: {"a": {"c": 2}}
    m := objx.New(map[string]interface{}{
      "a": map[string]interface{}{
        "b": 1,
    m.Set("a.c", 2)
    fmt.Println(m.JSON())  // output: {"a": {"b": 1, "c": 2}}
    opened by PeerXu 5
  • fix cc test reporter

    fix cc test reporter

    fixes the cc-test-reporter failure in GitHub workflow



    [Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

    • [x] Tests are passing: task test
    • [x] Code style is correct: task lint
    4. to release 
    opened by geseq 3
  • fix set within Map child element

    fix set within Map child element


    closes https://github.com/stretchr/objx/issues/97

    Fixes Set call when trying to set a value into an inner element that's a Map type as described in https://github.com/stretchr/objx/issues/97


    • [x] Tests are passing: task test
    • [x] Code style is correct: task lint
    4. to release 
    opened by geseq 3
  • Fix for map[interface{}]interface{} to JSON conversion

    Fix for map[interface{}]interface{} to JSON conversion

    If map[interface{}]interface{} end up within the Map, JSON() and MustJSON() fail even if the data is valid. Added methods to cleanup the data before converting to JSON.

    4. to release 
    opened by geseq 3
  • .Each(...) for MSI values

    .Each(...) for MSI values

    As it stands, Value.Each only works for slices; either a Map.Each or Value.MSIEach that accepts a function (e.g. func(key string, value interface{}) bool) would be nice.

    Although, I have an aversion to MSIEach just because it has "MSIE" in it. But that's just me.

    opened by nelsam 3
  • dealing with slices

    dealing with slices

    when I have the following json: [{"key": "value"}.{"key2": "value2"}]

    objx.FromJSON fails with the error: cannot unmarshal array into Go value of type objx.Map

    how should this be handled? I am using v.0.3.0

    opened by Digl 2
  • Direct access to array index broken?

    Direct access to array index broken?

    See this example: https://play.golang.org/p/meZ7CCSDrW0

    In this case, Has should return false, because the index 4 doesn't exist. Unless there's something I don't understand?

    opened by Thiht 2
  • Looking for maintainers

    Looking for maintainers

    I don't have the time to maintain this library any longer. Are there people interested in maintaining this library?

    The main tasks for the near future is to revisit the API for this library and push this to v1.0.

    help wanted 
    opened by hanzei 4
  • v0.4.0(May 8, 2022)

    • 6c797d8 Add helpers for slice of Map (#102)
    • 8dffac51 add github action (#106)
    • 31052d3 fix cc test reporter (#107)
    • 0ea374a fix nested array access (#104)
    • 4ff3852e fix int to float conversions (#108)
    • 27373ce fix set within Map child element (#105)
    Source code(tar.gz)
    Source code(zip)
  • v0.3.0(Jul 15, 2020)

  • v0.2.0(Apr 9, 2019)


    This release drops the support for go version less then 1.10.


    • ea4fe68 Move to go modules (#91)
    • d2ce263 Update to go 1.12 (#90)
    • ef50b0d Update to go 1.11 (#83)
    • d0444fc Update dependencies (#82)
    • b8b73a3 URLQuery with index slice keys (#74)
    • 9e1dfc1 Update dependencies (#81)
    • 0ab728f New tests for type_specific.go and fixed code (#75)
    • 652affc Add PULL_REQUEST_TEMPLATE.md (#77)
    • c8db58a Move type Map out of type_specific_codegen.go (#73)
    • fb88214 URLValues without sprinf, support for maps and slices (#63)
    • a5cfa15 Add go 1.10 tests && update dependencies (#67)
    • 2b6f327 When calling Set() with key pointing to nonexistent map path, the path will be created. (#66)
    • ca93b98 Convert floats to int when parsing JSON (#59)
    • 3f41636 Move tests to objx_test (#58)
    • fcc2171 Remove constants file (#57)
    • cfebd64 Codeclimate (#54)
    • 84b0369 Refactor accessors (#53)


    • c61a9df Fix for map[interface{}]interface{} to JSON conversion (#87)
    • d3a9fb1 Fix for #7 (#85)
    • 77d0150 Nil value returns empty string. (#76)
    • a97c7cc Fixed incorrect result for obj.Value().MSI() getter (#65)
    • 2532633 Fix indentation (#69)
    • 8a3f715 Fix bug introduced with #17 (#60)
    • e89b2c1 Fix ObjxMapSlice (#17)
    Source code(tar.gz)
    Source code(zip)
  • v0.1.1(Jun 10, 2018)



    • func MSI(keyAndValuePairs ...interface{}) Map does not longer panik, when called with wrong arguments


    • Added tests
    Source code(tar.gz)
    Source code(zip)
  • v0.1.0(Jun 26, 2018)

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