Extract value from a JSON Response Body via the Test Scripts

jgreene7930 · April 8, 2020, 11:29pm

I’m attempting to use a test script to store part of the response in an environment variable. Here’s the response that I’m attempting to parse:

{
    "meta": {
        "query_time": 1.61e-7,
        "trace_id": "bfa4ee6d-b15d-4920-8f9f-1a90bcb1b0b4"
    },
    "errors": [],
    "resources": [
        {
            "id": "xxxxxx",
            "group_type": "static",
            "name": "xxxxxx",
            "description": "xxxxxx",
            "assignment_rule": "xxxxx",
            "created_by": "xxxxx",
            "created_timestamp": "xxxxx",
            "modified_by": "xxxxx",
            "modified_timestamp": "xxxx"
        }
    ]
}

Here’s my test script code:

let responseData=pm.response.json();
console.log(responseData);
pm.environment.set("HostsToRemove", responseData.resources.name);

This fails with an error of “TypeError: Cannot read property of ‘name’ of undefined”. It appears to be because, under resources, there’s a set of brackets that seems to add another level to the JSON response. If i switch to responseData.meta.query_time then my code works perfectly. I just can’t figure out how to modify the response data values to get down 1 more level so I can reference the ‘name’ field. Any ideas?

danny-dainton · April 9, 2020, 8:33am

Hey @jgreene7930,

Welcome to the community!

Looking at your example response data - I can see that resources is an array which contains an object.

You would need to use resources[0].name to access the first object in the array.

You were on the right lines with logging the response to the Postman Console. This is what it would have logged:

Screenshot 2020-04-09 at 09.27.10

This is showing you that resources is an array with 1 object and if you were to expand this, you will see that the objects are zero-indexed. The first object would be 0 and that’s the reference that’s been added above [0].

So the full statement to set the variable would be:

let responseData = pm.response.json();
pm.environment.set("HostsToRemove", responseData.resources[0].name);

jgreene7930 · April 9, 2020, 2:45pm

Thank you! That makes total sense. I appreciate your help here.

test.vtw · June 29, 2021, 10:19am

Hi ,

I had a follow up question on this . My example response json is shown below
{
“cam:test”:“1970-01-01T00:00:00Z”,
“cam:test2”:“1970-01-01T00:00:00Z”,
“cam:test3”:“1970-01-01T00:00:00Z”,
“cam:test4”:1970
}

Could you please tell how do i retrieve the value when i have colon in the json field name

bpricilla · June 29, 2021, 12:02pm

Hi @test.vtw welcome to the community

Please read the similar post discussed here.

You should be using the bracket notation instead of dot notation.

For example,

let response=pm.response.json();
console.log(response);
pm.environment.set("camtest1", response['cam:test']);
pm.environment.set("camtest2", response['cam:test2']);

This is just based on the response you have provided above, please edit the path if needed I hope this helps!

DIS_Automation · November 12, 2021, 9:09am

Hi @bpricilla can you please help me extract and save the value of “id” inside ‘Body’ from below request
[

{

    "Id": 1,

    "StatusCode": 201,

    "Headers": {

        "Trace-Id": "af40c0f6-cae1-45b6-b925-08f03b95b6a5",

        "Content-Type": "application/hal+json; charset=utf-8",

        "Location": "/districts/b4668e48-1039-4822-91df-81883c3579f4/ag-club-affiliations/5802631a-06d9-4901-86b7-8525a34a84a5",

        "Content-Length": "1138"

    },

    "Body": {

        "message": "",

        "startDate": "2021-12-01",

        "endDate": "2022-06-30",

        **"id": "5802631a-06d9-4901-86b7-8525a34a84a5",**

        "_links": {

            "self": {

                "href": "/districts/b4668e48-1039-4822-91df-81883c3579f4/ag-club-affiliations/5802631a-06d9-4901-86b7-8525a34a84a5",

                "method": "GET|PATCH|DELETE"

            },

            "ag_club_affiliations": {

                "href": "/districts/b4668e48-1039-4822-91df-81883c3579f4/ag-club-affiliations",

                "method": "POST|PUT"

            },

            "individual": {

                "href": "/individuals/189d8777-5dab-408d-a759-5e4696d59df4",

                "method": "GET|PATCH"

            },

            "district": {

                "href": "/districts/b4668e48-1039-4822-91df-81883c3579f4",

                "method": "GET"

            },

            "club": {

                "href": "/clubs/1063969e-341a-40a4-9713-02a54c3079f4",

                "method": "GET|PATCH"

            }

        },

        "_embedded": {

            "organization": {

                "name": "Los Ejidos-Piura",

                "id": "1063969e-341a-40a4-9713-02a54c3079f4",

                "type": "Rotary_Club",

                "_links": {

                    "self": {

                        "href": "/clubs/1063969e-341a-40a4-9713-02a54c3079f4",

                        "method": "GET|PATCH"

                    }

                }

            },

            "individual": {

                "id": "189d8777-5dab-408d-a759-5e4696d59df4",

                "firstName": "cxDHYu",

                "lastName": "Au",

                "middleName": "yyblxb",

                "prefix": null,

                "suffix": null,

                "localizedName": null,

                "_links": {

                    "self": {

                        "href": "/individuals/189d8777-5dab-408d-a759-5e4696d59df4",

                        "method": "GET|PATCH"

                    }

                }

            }

        }

    }

},

{

    "Id": 2,

    "StatusCode": 201,

    "Headers": {

        "Trace-Id": "af40c0f6-cae1-45b6-b925-08f03b95b6a5",

        "Content-Type": "application/hal+json; charset=utf-8",

        "Location": "/districts/911ee7b9-197f-4ac5-b752-5e803e3a79f4/ag-club-affiliations/4ad8d5e4-9828-436b-b35a-9c3ad24a84a5",

        "Content-Length": "1140"

    },

    "Body": {

        "message": "",

        "startDate": "2021-12-01",

        "endDate": "2022-06-30",

        "id": "4ad8d5e4-9828-436b-b35a-9c3ad24a84a5",

        "_links": {

            "self": {

                "href": "/districts/911ee7b9-197f-4ac5-b752-5e803e3a79f4/ag-club-affiliations/4ad8d5e4-9828-436b-b35a-9c3ad24a84a5",

                "method": "GET|PATCH|DELETE"

            },

            "ag_club_affiliations": {

                "href": "/districts/911ee7b9-197f-4ac5-b752-5e803e3a79f4/ag-club-affiliations",

                "method": "POST|PUT"

            },

            "individual": {

                "href": "/individuals/aeefcad1-ef32-4d4b-8ade-17e25d64acf4",

                "method": "GET|PATCH"

            },

            "district": {

                "href": "/districts/911ee7b9-197f-4ac5-b752-5e803e3a79f4",

                "method": "GET"

            },

            "club": {

                "href": "/clubs/13e87aad-592b-43fc-86f1-5e2c696279f4",

                "method": "GET|PATCH"

            }

        },

        "_embedded": {

            "organization": {

                "name": "Malikipuram",

                "id": "13e87aad-592b-43fc-86f1-5e2c696279f4",

                "type": "Rotary_Club",

                "_links": {

                    "self": {

                        "href": "/clubs/13e87aad-592b-43fc-86f1-5e2c696279f4",

                        "method": "GET|PATCH"

                    }

                }

            },

            "individual": {

                "id": "aeefcad1-ef32-4d4b-8ade-17e25d64acf4",

                "firstName": "IvWI",

                "lastName": "pWrH",

                "middleName": "AuDmGTy",

                "prefix": null,

                "suffix": null,

                "localizedName": "Nagendra",

                "_links": {

                    "self": {

                        "href": "/individuals/aeefcad1-ef32-4d4b-8ade-17e25d64acf4",

                        "method": "GET|PATCH"

                    }

                }

            }

        }

    }

},

Kevin_Chang · October 7, 2022, 6:36pm

hey @DIS_Automation ~would you try this code?
let response=pm.response.json();
console.log(response);
pm.environment.set(“id”,response.Body.id);

roman.dushko · November 16, 2022, 1:00pm

Or there are might be a geeky long way to get it

const response = JSON.parse(Buffer.from(Array.from(pm.response.stream)).toString('UTF-8'))

before I learned pm.response.json()

Craigs · December 11, 2022, 1:55pm

Very new to Postman,
I’m trying to extract certain data from the response body and then use that data to send a post request this is where I’m at:

const response = pm.response.json();
const toolLtp = response.map(tool => tool.ltp)
console.log(toolLtp)

This is what my body is

{"status":"200","level":null,"message":"Success","data":{"ltp":1985.0,"Open":2000,"High":2110,"Low":1950}}

michaelderekjones · December 12, 2022, 10:41am

@Craigs

You don’t need to use map to get to the element you want.

let body = {
    "status":"200",
    "level":null,
    "message":"Success",
    "data":
    {
        "ltp":1985.0,
        "Open":2000,
        "High":2110,
        "Low":1950
    }
};


console.log(body.data.ltp); // 1985

Craigs · December 14, 2022, 8:48am

michaelderekjones:

let body = {
    "status":"200",
    "level":null,
    "message":"Success",
    "data":
    {
        "ltp":1985.0,
        "Open":2000,
        "High":2110,
        "Low":1950
    }
};

Thanks,
The ltp, Open, High and low in the body here changes frequently it is not a fixed value so i need to send a get request and only extract the ltp from the body, how do i do that.

michaelderekjones · December 14, 2022, 9:30am

@Craigs

I’m assuming you mean the value changes frequently, but the “ltp” key should always appear?

As long as the key stays the same, then the example I provided should work.

console.log(body.data.ltp); // 1985

Craigs · December 15, 2022, 6:14am

Yes, the value of LTP changes frequently so this is what I’m doing:
const response = pm.response.json();
let body = {
“status”:“200”,
“level”:null,
“message”:“Success”,
“data”:
{
“ltp”:1985.0,
“Open”:2000,
“High”:2110,
“Low”:1950
}
};
console.log(body.data.ltp); // 1985
so when i send a get request the value of ltp now has changed to 1990 but i still get 1985 i want to be able to get 1990 instead of 1985.

Thanks once again for helping me out here

michaelderekjones · December 15, 2022, 2:19pm

@Craigs

The “let body =” was just an example response I set for testing purposes.

Instead of parsing the response as I obviously don’t have access to your API. I just set a variable with the same format as the example body you provided.

It’s always going to return the figures that I hardcoded into the variable.

You would change this to the variable that you stored the parsed response.

const response = pm.response.json();
console.log(response.data.ltp);

If you are new to Postman. I would recommend going through the Postman training if you haven’t done so yet.

Postman Galaxy Training | Postman API Network

Run through the “APIs 101 Training”, then the “Testing and Automation Training” course.

andrezmolina247 · November 21, 2023, 3:48pm

Hi Everyone,

This is really useful, thank you for the contribution. I am dealing with a similar issue. I am trying to extract more than 1 value of the response and store them in different variables. (Ex: IP addresses). The test works if both values are the same(ex: enabled) but if I try with the IP it gives me the error “Couldn’t evaluate the test script:
ReferenceError: address is not defined”
Any idea of how could achieve that?

danny-dainton · November 21, 2023, 3:54pm

Hey @andrezmolina247

Welcome to the Postman Community!

What’s the full response body look like (mainly interested in the start of it)?

Is objects a actual property of the response or something that you have just added to the reference?

Does responseData[0]["ipv4-address"] work for you?

andrezmolina247 · November 21, 2023, 3:59pm

The one that you sent me doesn not work. If I do
pm.collectionVariables.set(“IP”, responseData.objects[0].enabled) it works

below the full response

{
    "objects": [
        {
            "comments": "",
            "enabled": true,
            "ipv4-address": "172.16.164.104",
            "ipv4-mask-length": "23",
            "ipv6-address": "Not-Configured",
            "ipv6-autoconfig": "Not configured",
            "ipv6-local-link-address": "Not Configured",
            "ipv6-mask-length": "Not-Configured",
            "name": "eth0",
            "type": "physical"
        },
        {
            "comments": "",
            "enabled": true,
            "ipv4-address": "7.7.7.2",
            "ipv4-mask-length": "30",
            "ipv6-address": "Not-Configured",
            "ipv6-autoconfig": "Not configured",
            "ipv6-local-link-address": "Not Configured",
            "ipv6-mask-length": "Not-Configured",
            "name": "eth1",
            "type": "physical"
        },
        {
            "comments": "",
            "enabled": true,
            "ipv4-address": "192.168.80.253",
            "ipv4-mask-length": "24",
            "ipv6-address": "Not-Configured",
            "ipv6-autoconfig": "Not configured",
            "ipv6-local-link-address": "Not Configured",
            "ipv6-mask-length": "Not-Configured",
            "name": "eth2",
            "type": "physical"
        },
        {
            "comments": "",
            "enabled": true,
            "ipv4-address": "127.0.0.1",
            "ipv4-mask-length": "8",
            "ipv6-address": "Not-Configured",
            "ipv6-autoconfig": "Not configured",
            "ipv6-local-link-address": "Not Configured",
            "ipv6-mask-length": "Not-Configured",
            "name": "lo",
            "type": "loopback"
        }
    ]
}

andrezmolina247 · November 21, 2023, 4:07pm

I just confirmed that the issue is related to the “-” character. If i try to do the same the with the value “name” where are different results it works. Still don’t know how to avoid that issue of the “-”

danny-dainton · November 21, 2023, 4:53pm

That makes sense, it’s the reason I added [0]["ipv4-address"] in my response.

Certain characters used as property keys like numbers, : or - etc will break the chained reference to the property. They would need to be referenced using bracket notation and not dot notation.

danny-dainton · April 11, 2024, 4:39pm

A post was split to a new topic: Comparing responses

Topic		Replies	Views
Extract value from a JSON Response Body via the Test Scripts - no output 🌱 Just Getting Started tests	2	8444	January 10, 2023
Can't Parse Specific Variable from Response Body 🌱 Just Getting Started variables	7	3131	May 4, 2022
Save a value from response as a environment variable 🙋 Help tests , variables , json	2	1688	June 17, 2021
How to get a value from variable when response in under id 🙋 Help tests	3	1410	October 16, 2021
Need help in extracting the value 🌱 Just Getting Started tests , variables , collections	7	5525	September 27, 2019

Extract value from a JSON Response Body via the Test Scripts

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