How to set a JSON string to Postman variable and use it in the Body?

Question

In Postman, I want to pass a dynamic JSON string to a variable and use it in a request. This is what I have:

Pre-request:

var myJsonString = "{ \"type\": \"10\", \"number\": \"123456\" }";

pm.variables.set("my-json-string", myJsonString);

Body:

"body":{
     "jsonString":"{{my-json-string}}"
}

But this does not work. Do you know any solution for this?

If I send the request like this, it works perfect:

"body":{
     "jsonString":"{ \"type\": \"10\", \"number\": \"123456\" }"
}

Danny Dainton · Accepted Answer · 2018-08-29 06:40:33Z

1

Have you tried wrapping it with JSON.stringify()?

pm.globals.set("my-json-string", JSON.stringify(myJsonString))

As this value is saved as a string, you will not need to use the delete double-quotes on variable within the Post body:

"jsonString":{{my-json-string}}

answered Aug 25, 2018 at 6:29

Danny Dainton

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1 Comment

Does this answer the question?

Michael Cauduro · Accepted Answer · 2022-06-24 09:29:36Z

0

you need to store it using JSON.stringify

let response = pm.response.json(),
jsonVariable = JSON.stringify(response);
pm.environment.set("yourVariable", jsonVariable );

And then use it in another like:

"yourVariable":"{{yourVariable}}",

answered Jun 24, 2022 at 9:29

Michael Cauduro

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