Global variables in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Postman Global Variables Scope

In Postman, where are global variables accessible?

A Across all collections and requests in the current Postman workspace

B Only within the current request and its scripts

C Only within the current collection

D Only within the current environment

💡 Hint

Think about variables that are shared everywhere in Postman.

Global variables in Postman are accessible across all collections and requests within the workspace, unlike environment variables which are limited to a specific environment.

❓ Predict Output

intermediate

Output of Setting and Getting a Global Variable

What will be the output of the following Postman test script?

Postman

pm.globals.set('token', 'abc123');
const token = pm.globals.get('token');
console.log(token);

A abc123

B undefined

C null

D Error: pm.globals is not defined

💡 Hint

Consider what value is stored and then retrieved.

The script sets the global variable 'token' to 'abc123' and then retrieves it. The console.log will output 'abc123'.

❓ assertion

advanced

Correct Assertion for Global Variable Value

Which assertion correctly verifies that the global variable 'userId' equals '42' in a Postman test script?

Postman

const userId = pm.globals.get('userId');

A pm.test('User ID is 42', () => pm.expect(userId).to.eql(42));

B pm.test('User ID is 42', () => pm.expect(userId).to.be(42));

C pm.test('User ID is 42', () => pm.expect(userId).to.equal('42'));

D pm.test('User ID is 42', () => pm.expect(userId).toBe('42'));

💡 Hint

Remember the type of the value returned by pm.globals.get.

pm.globals.get returns a string, so the assertion must compare to the string '42' using .to.equal().

🔧 Debug

advanced

Debugging Global Variable Not Updating

A tester sets a global variable in the Pre-request Script using pm.globals.set('session', 'xyz'), but in the Tests script, pm.globals.get('session') returns undefined. What is the most likely cause?

A The variable was deleted before the Tests script runs

B Global variables cannot be set in Pre-request Scripts

C The Tests script runs before the Pre-request Script

D The variable name is misspelled in the Tests script

💡 Hint

Check spelling carefully in both scripts.

If the variable name is misspelled in the Tests script, pm.globals.get will return undefined because it looks for a different variable.

❓ framework

expert

Best Practice for Managing Global Variables in Postman Collections

Which approach is best to avoid conflicts and ensure maintainability when using global variables across multiple Postman collections?

A Use generic global variable names like 'token' or 'id' for all collections

B Prefix global variable names with collection-specific identifiers, e.g., 'coll1_token'

C Set and delete global variables dynamically in each request without naming conventions

D Avoid using global variables and use only environment variables instead

💡 Hint

Think about how to prevent variable name clashes.

Prefixing global variable names with collection-specific identifiers helps prevent conflicts and improves clarity when multiple collections use global variables.