Path parameters in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Path Parameters in API Requests

In Postman, what is the primary purpose of using path parameters in an API request URL?

A To define the request body format

B To specify dynamic parts of the URL that identify specific resources

C To add query filters to the API request

D To set HTTP headers for authentication

💡 Hint

Think about how URLs change to access different items in a collection.

Path parameters are used to specify dynamic segments in the URL that point to specific resources, like user IDs or product codes.

❓ Predict Output

intermediate

Output of a Postman Request with Path Parameters

Given the API endpoint https://api.example.com/users/:userId/orders/:orderId and path parameters userId=42 and orderId=1001, what is the final URL sent by Postman?

A https://api.example.com/users/1001/orders/42

B https://api.example.com/users/:userId/orders/:orderId

C https://api.example.com/users?userId=42&orderId=1001

D https://api.example.com/users/42/orders/1001

💡 Hint

Path parameters replace placeholders in the URL path, not query strings.

Path parameters replace the placeholders in the URL path with actual values, forming the final URL.

❓ assertion

advanced

Validating Path Parameter Usage in Postman Tests

Which Postman test script assertion correctly verifies that the userId path parameter in the request URL is 123?

Postman

pm.test('UserId path parameter is 123', () => {
  const url = pm.request.url.toString();
  // Assertion here
});

A pm.expect(pm.request.url.path[1]).to.eql('123');

B pm.expect(pm.request.url.query.get('userId')).to.eql('123');

C pm.expect(pm.request.url.variables.get('userId')).to.eql('123');

D pm.expect(url).to.include('/users/123/');

💡 Hint

Path parameters appear in the URL path array, not in query or variables directly.

In Postman, pm.request.url.path is an array of path segments. The userId is usually the second segment if the path is like /users/123.

🔧 Debug

advanced

Debugging Path Parameter Replacement Issue

A Postman request URL is https://api.example.com/items/:itemId/details. The path parameter itemId is set to 789, but the request is sent with the URL https://api.example.com/items/:itemId/details (no replacement). What is the most likely cause?

A The path parameter <code>itemId</code> was not defined in the Postman collection or environment variables

B The HTTP method is incorrect and prevents path parameter substitution

C The request body is missing, causing the URL to not update

D The server is rejecting the request and returning the original URL

💡 Hint

Check if the variable name matches exactly and is defined.

If the path parameter variable is not defined in Postman environment or collection variables, Postman cannot replace the placeholder in the URL.

❓ framework

expert

Automating Tests for Path Parameters in Postman Collections

Which approach best automates testing multiple path parameter values in a Postman collection run?

A Write a pre-request script that randomly generates path parameter values without external data files

B Manually change the path parameter value in the URL before each request and run the collection multiple times

C Use a Postman collection runner with a CSV file containing different path parameter values and reference them in the URL

D Use Postman monitors to schedule requests without changing path parameters

💡 Hint

Think about how to run the same request multiple times with different inputs automatically.

Using the collection runner with a CSV file allows you to supply multiple sets of path parameter values and run tests automatically for each set.