Postman - How to get a value from a JSON array inside a JSON object

Question

I am new to JSON and Postman. I think I'm trying to do something very simple.

I have created a POST request which will get a JSON response like the one below.

In the example below from inside of the FieldGroups array I want to get the value of Id but only if the value of Name is General

How can I do it? Thanks in advance.

{
    "Id": 1328,
    "Name": "AAA Test",
    "Owner": {
        "Id": 208,
        "Name": "The Boss"
    },
    "FieldGroups": [
        {
            "Id": "c81376f0-6ac3-4028-8d61-76a0f815dbf8",
            "Name": "General",
            "FieldDefinitions": [
                {
                    "Id": 1,
                    "DisplayName": "Product Name"
                },
                {
                    "Id": 2,
                    "DisplayName": "Short Description"
                },
                {
                    "Id": 33,
                    "DisplayName": "Long Description"
                },
            ]
        },
        {
            "Id": "5ed8746b-0fa8-4022-8216-ad3af17db91f",
            "Name": "Somethingelse",
            "FieldDefinitions": [
                {
                    "Id": 123,
                     "DisplayName": "Attribution"
                },
                {
                    "Id": 1584,
                    "DisplayName": "FC1"
                },
                {
                    "Id": 623,
                    "DisplayName": "Sizes",
                    "Owner": {
                        "Id": 208,
                        "Name": "The Boss"
                    },
                    "Unit": "",
                    "Options": [
                        {
                            "Id": 1,
                            "Value": "XS"
                        },
                        {
                            "Id": 2,
                            "Value": "S"
                        },
                        {
                            "Id": 3,
                            "Value": "M"
                        },
                    ]
                }
             ]
        }
    ],
    },
    "Version": 1
}

Answer 1

Postman has built-in support of a JavaScript utility library called Lodash (the _ in the code) and you can use its features to loop through the JSON array in a more consice way.

Since I am not exactly sure what you want to achieve, just try to adapt below code to your problem.

// Convert the response body to a JSON object
var jsonData = pm.response.json()

// Create a variable to which you will assign the value of Id later on
var generalId;

function setGeneralID() {
    _.each(jsonData.FieldGroups, (arrayItem) => {
        if(arrayItem.Name  === 'General') {
            // Assign the value of Id to the generalId variable
            generalId = arrayItem.Id;

            // OR (depending on what you want to do)
            // Create a Postman environment variable and assign the value of Id to it
            pm.environment.set("Id", arrayItem.Id);
        }
    });
}

I hope I could help.